indiPDF Documentation

Complete user guide for indiPDF — the advanced PDF editor for Linux, macOS, and Windows.

1. Getting Started

indiPDF is a powerful PDF editor that runs natively on Linux, macOS, and Windows. It provides annotation, form filling, page management, OCR, scanning, signatures, and more — all without a subscription or cloud dependency. Your documents never leave your computer.

Download indiPDF from the product page, install it using one of the methods listed in the Installation section, and open your first PDF to get started.

2. The Interface

The indiPDF window is organized into five areas:

Header bar — Open, Save buttons, document tabs, and the search box.
Menu bar — Full access to every feature via File, Edit, View, Search, Tools, and Help.
Toolbar — One-click access to annotation, drawing, and editing tools. Contextual controls (color picker, font selector, stroke width) appear based on the active tool.
Sidebar — Page thumbnails for quick navigation, drag-to-reorder, and batch selection. Toggle with F9.
Main viewer — Your PDF document. Scroll to navigate; use Ctrl+Scroll to zoom.

Dark Mode

indiPDF automatically follows your operating system's light/dark theme preference. On Linux it checks GTK settings, the XDG portal, and environment variables. On macOS and Windows it uses the native system appearance.

Interface Size

indiPDF doesn't inherit your desktop's font size, so if you run a large system font the menus and toolbar may still look small. View → Interface Size scales them from 100% up to 200%.

This affects the interface only — menus, toolbar, tabs, sidebar and dialogs. The document itself is unchanged; use the zoom controls (Ctrl++ / Ctrl+-) for that. The setting is remembered between sessions.

Page Appearance (High Contrast & Inverted)

If white pages are hard to read, View → Page Appearance offers two reading aids:

Invert Lightness — dark pages with light text, the way Okular's inverted view works. Colours keep their hue, so blue headings stay blue rather than turning orange.
High Contrast — the same inversion with the contrast pushed further, for maximum legibility.

Annotations are inverted along with the page, so your highlights and notes stay visible against it. Form fields and links are left alone so they remain readable as controls.

This changes only how the document is displayed. Saving, printing and exporting are completely unaffected, and the setting is remembered between sessions.

Language

The interface is available in English, Spanish, French, German, Brazilian Portuguese, Italian, Dutch, Greek, and Japanese. indiPDF follows your system language automatically; to override it, choose a language under View → Language.

3. Opening & Creating Documents

There are several ways to open a PDF:

File → Open or Ctrl+O
Click the Open button in the header bar.
Click Open PDF on the welcome screen.
Select a file from File → Open Recent.
Double-click a .pdf file in your file manager (if indiPDF is set as the default).
Drag and drop a PDF onto the application window.

Multiple Documents

Each opened PDF appears as a tab. Click a tab to switch between documents, or use Ctrl+W to close the active tab.

Encrypted PDFs

If a PDF requires a password, indiPDF will prompt you to enter it. Permission-only PDFs (those with an empty user password) open automatically.

Creating a Blank Document

Start from an empty page and build a document — or a fillable form — from scratch:

Select File → New Blank Document (or click New Blank Document on the welcome screen).
Choose a page size (Letter, Legal, A4, A5, or Tabloid), portrait or landscape orientation, and how many pages to start with.
Click Create. The document opens as an unsaved "Untitled.pdf" tab.

Use the text, shape, image, and form field tools to build out the page. You can append another blank page at any time via File → Add Pages → Add blank page.

4. Saving Documents

Save Options

Save (Ctrl+S) — Overwrites the current file. If the document hasn't been saved before, you'll be prompted to pick a location.
Save As (Ctrl+Shift+S) — Save a copy to a new file name or location.
Save & Flatten — Permanently bakes all annotations into the PDF. The result is viewable in any PDF reader, but annotations can no longer be edited in indiPDF.

Annotations vs. Flattening

A normal save keeps annotations editable. indiPDF also writes standard PDF annotation objects (ISO 32000), so other readers like Acrobat, Foxit, and Evince can display them. Use Save & Flatten when you need maximum compatibility — for example, when emailing a marked-up document to someone.

An unsaved document shows a dot (•) on its tab. Use Ctrl+S frequently to avoid losing work.

5. Navigation & Zoom

Scrolling & Zooming

Scroll — Mouse wheel or trackpad to move through pages.
Zoom in — Ctrl++ or Ctrl+Scroll up
Zoom out — Ctrl+- or Ctrl+Scroll down
Fit to width — Ctrl+0
Set default zoom — View → Set Current Zoom as Default

Two-Page (Book) View

Toggle the book-spread layout with the toolbar button or Ctrl+Shift+B. Pages are laid out side-by-side like an open book — the first page sits alone on the right as a cover, then pages pair up (2–3, 4–5, …). Fit to width (Ctrl+0) sizes the whole spread to the window.

Page Navigation

Click any thumbnail in the sidebar to jump directly to that page. You can also use search results or the Outline panel to navigate.

Searching

Press Ctrl+F or click the search box in the header.
Type your search term.
Use Ctrl+G (next) or Ctrl+Shift+G (previous) to cycle through results.
Click the X to clear the search.

6. Bookmarks & Outline

The Outline panel shows the document's bookmarks — and lets you edit them.

Navigating

Open the Outline tab in the sidebar (F9 toggles the sidebar). Click any entry to jump to its page; use the chevrons to expand or collapse nested entries.

Editing Bookmarks

Add — Click the + button in the panel header to bookmark the current page.
Add a child — Hover over an entry and click the nest icon to add a sub-bookmark beneath it.
Rename — Double-click an entry (or use the pencil icon), type the new title, and press Enter.
Delete — Hover and click the trash icon. Deleting an entry with children asks for confirmation.

Bookmarks are written into the PDF as standard outline entries when you save, so they work in every PDF reader — Acrobat, Evince, browser viewers, and more.

7. Text Markup (Highlight, Underline, Strikethrough)

Text markup tools let you highlight, underline, or strikethrough existing text in your PDF.

Applying Markup

Select the desired tool — Highlight, Underline, or Strikethrough — from the toolbar.
Click and drag across the text you want to mark up.
The markup is applied when you release the mouse. Multi-line selections are supported.

Changing Colors

Before applying markup, pick a color with the color selector in the toolbar. Your chosen color is remembered between sessions.

Removing Markup

Switch to the Select tool (or press Escape).
Click on the markup annotation.
Press Delete or Backspace.

Multi-line selections undo together as one action with Ctrl+Z.

8. Text Annotations

Add free-form text boxes anywhere on your PDF.

Adding Text

Select the Text tool from the toolbar.
Click anywhere on the page for a default-size box, or drag to lay out the box dimensions before typing.
Start typing. Press Enter for a new line — multi-line text is preserved when you save, flatten, or print.
Click outside to finish.

Formatting

While the text tool or a text annotation is active, the toolbar shows:

Font family dropdown
Font size selector
Text color picker

Changes apply immediately to the active annotation. Settings persist between sessions.

Moving & Resizing

Move — Click and drag the text box.
Resize — Drag any corner or edge handle.
Edit — Double-click to re-enter editing mode.

9. Comments

Attach notes to specific text selections, similar to commenting in a word processor.

Select the Comment tool (or press Ctrl+M).
Select the text you want to comment on.
Type your comment in the popup that appears.
Click outside to save.

Commented text is highlighted. Click on it to view or edit the comment.

10. Link Annotations

Add clickable hyperlinks to your PDF.

Select the Link tool from the toolbar.
Select the text you want to make into a link.
Enter the URL in the popup dialog.
Click OK.

Links appear with a blue underline and are clickable in any PDF viewer.

11. Drawing & Shapes

Freehand Drawing

Select the Draw (freehand) tool.
Choose a color and stroke width from the toolbar. Stroke width ranges from 1 to 12 pt.
Click and drag to draw. Hold Shift to draw a straight line from the starting point.
Release to finish the stroke.

Use the [ and ] keys to quickly cycle through stroke sizes.

Eraser

Select the Eraser tool and drag over freehand strokes to remove them. The eraser can split strokes — only the erased segment is removed.

Shapes

Click and drag to create:

Rectangle — Filled or outline
Circle / Ellipse — Filled or outline
Arrow — Line with an arrowhead. Supports custom stroke width.

Toggle between solid (filled) and outline styles using the fill-style selector in the toolbar.

12. Editing the Document’s Own Text

This changes what the document says, rather than adding a note on top of it. Use it to correct a typo, change a figure, or rewrite a sentence in a PDF you did not write.

Choose the Edit Text tool from the toolbar.
Select the words you want to change.
Right-click the selection and choose Edit for those words, or Edit Whole Paragraph to work on the paragraph they sit in.
Type the replacement and confirm.

Edit, or Edit Whole Paragraph?

Edit covers the words you selected and draws the replacement over them. It is the right choice when the new text is about the same length as the old — a date, a name, a figure.

Edit Whole Paragraph hands you the whole paragraph and re-breaks its lines when you are done. Use it whenever the replacement is longer than what it replaced: a plain edit cannot re-wrap the line, so a longer phrase would run past the margin or over its neighbour.

If the rewritten paragraph needs more room than the paragraph had, indiPDF tells you how many lines over it is rather than letting it overflow where you might not notice. The text is yours, so the edit is not refused — only reported.

Matching the Page

indiPDF reads the typeface, weight and slant of the text being replaced, and the ink and paper colours around it, so the replacement sits in the page rather than on it. Documents are not always co-operative: where the original uses a font that is not installed, indiPDF substitutes the closest one it has.

Note: a PDF only carries the letters it actually uses. If a document’s font was embedded with just the characters on the page — which is very common — a letter or digit that does not appear anywhere in it cannot be drawn from that font, and indiPDF will substitute.

13. Editing What Is Already on the Page

Every other tool in indiPDF adds something on top of a page. This one changes the page itself — the lines, boxes, shapes and images the document was drawn with. It is what you want for rearranging sheet music, tidying a diagram, or removing a rule from a form.

Selecting

Choose the Edit page objects tool (the shapes icon).
Move the pointer over the page. Elements light up as you pass over them.
Click one to select it, or drag across the page to select everything the band touches. Click an empty area to deselect.
Shift-click adds an element to the selection, or removes it. Ctrl+A selects everything on the page.

Selecting a band is how you take something built from many pieces — a system of music, a row of a table, a block of a diagram — since each line, note and symbol is a separate element. Everything selected moves, copies and deletes together.

Selection follows the actual shape rather than a box around it, so a hairline rule or a staff line is as easy to click as a large block. A filled shape can be clicked anywhere inside it; an outlined one is picked up by its edge, so you can click straight through the middle of a frame to whatever is behind it.

Moving, Copying and Deleting

Move — drag any part of the selection; it all moves together.
Delete — press Delete, or use the button in the bar at the bottom of the window.
Copy — press Ctrl+D. The copies appear slightly offset from the originals so you can drag them where you want them.
Copy to another page — use Copy to page… in the bar at the bottom and give a page number. The copy lands in the same position it occupied on the original page.
Undo — Ctrl+Z steps back through changes.

What Can and Cannot Be Changed

Text moves, copies and deletes like anything else — useful for a notehead, a symbol or a stray word. To change what text says, use Edit Text instead. Occasionally a piece of text is pinned in place because the words after it start where it ends; indiPDF says so, and deleting it still works.
Repeated elements — some documents draw a thing once and re-use it in several places. indiPDF marks these with a dashed outline and leaves them alone, because changing one would change all of them.
Scanned pages are a single image, so there is nothing separate on them to select. Use OCR or Redaction for those.
Very dense pages — a detailed map, a plan exported from CAD — can be built from tens of thousands of separate elements, too many to pick out one at a time. indiPDF says how many there are rather than offering a selection that would be unusable. Every other tool works on such a page as usual.
A small number of pages use an older way of storing images that cannot be rewritten safely. indiPDF says so rather than risk damaging the page.

Elements are individual drawing operations, which is not always the same as what looks like one object: a shape drawn as four separate strokes selects as four. Dragging a band over it takes all four at once.

14. Signatures

Create and apply handwritten-style signatures to your documents. (For cryptographic signing with a certificate, see Digital Certificate Signatures.)

Creating a Signature

Select the Signature tool. The signature dialog offers four tabs:

Draw — Use your mouse or trackpad to draw a freehand signature.
Type — Type your name and choose from six bundled handwriting-style fonts: Dancing Script, Great Vibes, Caveat, Pacifico, Sacramento, and Satisfy.
Upload — Import a signature image (PNG, JPG, GIF). If you upload a photo or scan of a signature on paper, indiPDF removes the white background automatically so the signature doesn't sit in a white box over your document. The preview shows the result on a chequered background, and a Remove white background tick box turns it off if you'd rather keep the image as-is.
Saved — Select a previously saved signature for one-click placement.

Click Save Signature to store it for future use. Saved signatures persist across sessions.

Placing a Signature

After selecting or creating a signature, click on the page where you want it placed. If you have exactly one saved signature, it is placed directly — no dialog required.

Managing Signatures

Go to Tools → Manage Signatures to view, create, or delete signatures without needing to place one on a document.

15. Digital Certificate Signatures

Sign documents cryptographically with a PKCS#12 certificate, and verify signatures on documents you receive. Signed documents open with the signature intact in any PDF reader, including Acrobat.

Signing a Document

Go to Tools → Digital Signature.
Click Choose certificate and select your .p12 or .pfx file (RSA certificates are supported), then enter its password.
Optionally add a signing reason and location, and choose whether to show a visible signature stamp on a page of your choice.
Click Sign and Save As… and pick a destination.

Signing saves a signed copy of the document, including all current annotations and form values. Any edit made after signing invalidates the signature — sign as the final step.

Verifying Signatures

The same dialog lists every certificate signature in the open document, showing the signer, issuer, signing time, and reason. Each signature is verified cryptographically: if the document has been modified since it was signed, the signature is flagged as invalid.

Note: indiPDF verifies the signature itself and detects tampering, but does not evaluate the certificate's chain of trust against a certificate-authority store.

16. Stamps

Add pre-made or custom rubber stamps to your documents.

Built-In Stamps

Select the Stamp tool and click on the page. A picker shows built-in stamps (Approved, Rejected, Draft, Paid, etc.). Click one to place it.

Custom Stamps

Click Custom… in the stamp picker to create your own. Custom stamps support multi-line text and customizable colors, and are saved automatically — they appear in a Your Stamps section of the picker across sessions. Hover over a saved stamp to remove it.

17. Images

Select the Image tool.
Click where you want to place the image.
Choose an image file (PNG, JPEG, WebP, etc.) from your computer.
The image is inserted at the clicked location. Drag the corner handles to resize.

18. Form Filling

indiPDF handles interactive PDF forms, including government and tax forms.

Text fields — Click and type.
Checkboxes — Click to toggle.
Radio buttons — Click to select.
Dropdown menus — Click and choose from the list.

Calculated Fields

Forms with JavaScript-based calculations (totals, averages, auto-fill) are evaluated automatically as you type.

Saving Form Data

Form data is saved with the document. Use Save & Flatten if you need to share the filled form and ensure the values are visible everywhere.

To build your own fillable forms, see Creating Forms.

19. Creating Forms (Form Designer)

Build fillable forms on any document — or start from a blank document. Fields you create become real PDF form fields that work in every reader.

Placing Fields

Pick a field tool from the toolbar: Text field, Checkbox, or Dropdown.
Drag on the page to place and size the field. For a checkbox, drag a wide box — the checkbox itself stays square at the left, and the label sits beside it.
The properties dialog opens automatically. Set the visible Label, the internal field name, dropdown options (one per line), or the multi-line flag for text fields.

While designing, fields appear as dashed blue boxes. Move and resize them like any annotation; double-click one (or select it and click the gear) to reopen its properties. Labels are placed as regular text, so you can move or edit them independently at any time.

Saving the Form

When you save the document, designed fields are converted into real, fillable AcroForm fields. The document reloads and the fields are immediately fillable — in indiPDF and in any other PDF reader.

Editing Fields Later

Click Edit existing form fields (the pencil-square button in the form tools group) to convert the document's text fields, checkboxes, and dropdowns back into editable design boxes. Move, resize, rename, change options, or delete them, then save again. Values already entered in the fields are preserved. Radio groups, buttons, and signature fields are left untouched.

20. Redaction

Permanently remove sensitive content from a document. Unlike drawing a black rectangle over text — which leaves the content underneath fully recoverable — applied redactions delete the content from the file itself.

Redacting Content

Select the Redact tool (shield icon) from the toolbar.
Drag boxes over the content you want removed. Marks appear as hatched black rectangles — at this stage they are only visual covers.
Click Apply Redactions (the shield-check button next to the Redact tool) and confirm.
Save the document.

How It Works

Applying redactions removes the covered text and images from the document — nothing can be selected, copied, searched, or extracted afterwards. Pages containing redactions are converted to flattened images, and interactive elements on those pages (links, form fields) are removed.

There is no undo, but your file on disk only changes when you save: save to make the redaction permanent, or close without saving to keep the original.

Important: unapplied redaction marks only cover content visually. If you save or flatten while marks are still unapplied, indiPDF warns you and offers to apply them first.

21. OCR (Text Recognition)

OCR (Optical Character Recognition) extracts text from scanned documents, making them searchable and editable.

Requirements

OCR requires Tesseract. On Windows and in the Flatpak, it is bundled — no install needed. Elsewhere:

Ubuntu / Debian: sudo apt install tesseract-ocr
Fedora: sudo dnf install tesseract
macOS: brew install tesseract

For additional languages, install the appropriate language pack (e.g., tesseract-ocr-deu for German).

If you have installed Tesseract yourself — to add languages, or because the bundled copy is not being found — indiPDF looks in the usual places for it, including C:\Program Files\Tesseract-OCR on Windows and a per-user installation under %LOCALAPPDATA%. It uses the language files that came with whichever copy it finds, so the languages you installed are the ones available.

Note: the official Tesseract installer for Windows leaves its “add to PATH” option unticked. That does not matter to indiPDF, which looks in the install locations directly.

Running OCR

Open a scanned or image-based PDF.
Go to Tools → OCR.
Choose the language(s) for recognition.
Choose an output mode (see below).
Select pages to process (all, current, or custom range).
Click Start OCR.

Output Modes

Make searchable (default) — Adds an invisible text layer beneath the scan. The page looks exactly the same, but the text becomes searchable, selectable, and copyable in any PDF reader. Recommended for archiving scanned documents.
Convert to editable text — Covers the scanned text with editable text boxes you can correct and reposition, then Save & Flatten to produce the final document. Changes how the page looks; use it when you need to fix or rewrite the recognized text.

22. Scanning Documents

Scan paper documents directly into indiPDF.

Requirements by Platform

Linux: SANE — sudo apt install sane-utils (Debian/Ubuntu) or sudo dnf install sane-backends (Fedora)
macOS: SANE via Homebrew — brew install sane-backends
Windows: WIA (built in). Any WIA-compatible scanner is detected automatically.

Scanning a Document

Connect and power on your scanner.
Go to Tools → Scan.
Select your scanner from the dropdown.
Choose settings. The options offered are the ones your scanner actually reports — a scanner with no document feeder has no source to choose, so no source setting appears.
Click Scan. Repeat for additional pages.
Click Create PDF to assemble scanned pages into a document.

Your scanner preference is remembered. Check "Add to current document" to append scanned pages to an open PDF. Use 300 DPI for documents you plan to OCR.

23. Adding Non-PDF Content

indiPDF can import various file types and add them as pages.

Supported File Types

Images: PNG, JPEG, WebP, GIF, BMP, TIFF
Office Documents: DOCX, DOC, ODT, XLSX, XLS, ODS, CSV, PPTX, PPT, ODP
Text Files: TXT, RTF, Markdown

How to Add

With a document open, select File → Add Pages (or click Add Pages in the toolbar).
Select one or more files.
Files are converted to PDF pages and appended to your document.

Office Document Conversion

Conversion is tiered — indiPDF automatically uses the best converter available:

Windows: An installed Microsoft Office is used automatically for perfect fidelity. No configuration needed.
All platforms: LibreOffice or OnlyOffice is used when installed.
Built-in: DOCX, XLSX, CSV, TXT, and Markdown convert out of the box with no external software — including in the Flatpak.

Only legacy and presentation formats (DOC, ODT, XLS, ODS, PPT/PPTX, ODP, RTF) require Microsoft Office, LibreOffice, or OnlyOffice:

Ubuntu / Debian: sudo apt install libreoffice
Fedora: sudo dnf install libreoffice
macOS: brew install --cask libreoffice
Windows: Download from libreoffice.org (if you don't have Microsoft Office)

24. Page Management

Rotating Pages

Press Ctrl+R (or View → Rotate Page) to rotate the current page 90° clockwise. Rotations are saved with the document.

Selecting Pages

Open the sidebar (F9). Click a thumbnail to go to that page.

Ctrl+Click adds and removes individual pages from a selection.
Shift+Click selects everything between the last page you clicked and the one you click now.

Selected pages are outlined in the accent colour and the sidebar heading says how many. The page you are currently viewing keeps its ring, so you can still see where you are inside a selection.

Reordering Pages

Drag a thumbnail to move it. Drag any page of a selection and the whole selection goes with it, gathering into a block where you drop it — pages 2, 4 and 6 dragged to the front become pages 1, 2 and 3, and the pages that were between them close up.

Ctrl+Z puts them all back in one step.

Deleting Pages

Single page: Right-click a thumbnail and select Delete Page.
Several at once: Select them as above. A Delete N button appears in the sidebar header.

Adding Pages from Another PDF

Click Add PDF in the toolbar or use File → Add Pages.

The dialog asks where the new pages should go: at the end, before page N, or after page N. The page number starts at whichever page you were looking at when you opened the dialog, and the end is the default.

Several files added in one go keep the order you chose them in.

25. Crop & Trim

Crop pages visually, like an image editor.

Go to Tools → Crop / Trim.
A crop overlay appears on the current page with eight resize handles and a dimmed exterior.
Drag the handles to define the visible area. Drag the interior to move the crop rectangle.
Use the floating action bar to Apply to Current Page or Apply to All Pages.

Cropping uses the PDF CropBox — original content is preserved but hidden outside the crop area. This is non-destructive.

26. Splitting & Merging

Merging PDFs

Click Merge in the toolbar or select File → Merge PDFs.
Add the PDF files you want to combine.
Drag to reorder.
Click Merge to create a new combined document.

Form fields from all source PDFs are preserved in the merged document.

Splitting PDFs

Click Split in the toolbar.
Choose how to split: extract specific pages or define page ranges.
Choose a save location.

27. Document Compare

See exactly what changed between two versions of a document.

Open one of the documents, then go to Tools → Compare Documents.
Click Choose PDF to compare and select the other version.
Step through page pairs with the arrow buttons.

Reading the Results

Both pages are shown side by side, with every changed region outlined in red on both panes.
A status badge reports Identical or the number of differing regions per page. Missing pages and page-size changes are flagged as differences.
Enable Show text changes for a line-by-line list of added (+) and removed (−) text.

The compare view is a floating window — drag its title bar to move it, resize from any edge, or maximize it. It remembers its position and size, and the document behind stays usable while it's open.

28. Bates Numbering

Stamp sequential identification numbers across every page — a staple of legal document production.

Go to Tools → Bates Numbering.
Set the prefix and suffix (e.g., ACME-), the start number, and the number of digits for zero-padding.
Choose the position (header or footer), alignment (left, center, right), and font size. A live preview shows the first and last numbers.
Click Apply.

Numbers are stamped permanently into the page content and continue sequentially across the document (e.g., ACME-000001 through ACME-000042). Numbers read upright on rotated pages.

29. Exporting (Images, Text, Word, Excel, ODT, ODS)

Select File → Export (or click Export in the toolbar) and choose a format.

Export as Images or Text

PNG / JPEG — Select pages and resolution/quality; annotations are included in the output.
Plain text (.txt) — Extracts the document's text.

Export to Word (.docx)

For the best layout fidelity, indiPDF uses Microsoft Word (Windows) or LibreOffice when installed. When neither is available, a built-in converter extracts the text into a .docx — the content comes through, but complex layouts are simplified.

Export to Excel (.xlsx)

Rebuilds rows and columns from each page's text layout — a fast way to get tables out of a PDF and into a spreadsheet. Each page becomes a worksheet. Works entirely built-in, no external software required.

Export to LibreOffice Calc (.ods)

Exports the reconstructed tables as an OpenDocument Spreadsheet, using the same row and column detection as Excel export — one sheet per page. Unlike Writer export this is built in, so it needs no external software and works in every build, including the Flatpak.

Export to LibreOffice Writer (.odt)

Exports the document as OpenDocument Text, for editing in LibreOffice Writer or any other OpenDocument-capable editor.

Like Word export, this is tiered: LibreOffice or OnlyOffice is used when available for the best layout fidelity, and when neither can be reached a built-in converter extracts the text into an .odt instead. The content comes through either way; only complex layouts are simplified.

Flatpak note: the Flatpak cannot see programs installed on your system, so it always uses the built-in converter — the export works, but without layout fidelity. Use the AppImage, DEB or RPM build if you need that — see System LibreOffice not used for conversion.

See also PDF/A Export for archival-format output.

30. Batch Convert

Do one thing to a lot of documents. Tools → Batch Convert needs no document open, since it picks its own.

Choose individual files, or point it at a whole folder.
Pick what to turn them into: Word, Writer, Excel, Calc, plain text, or a compressed PDF.
Choose where the results go.
Start the run. Progress is reported per document, and you can stop part-way.

What Happens to Awkward Files

Each document is converted on its own, so one that is damaged or unreadable is reported against its own name and the rest carry on. A run of three hundred tells you which three went wrong rather than stopping dead at the first.

Nothing already in the destination folder is overwritten. A name that clashes with an existing file is numbered instead.

Note: converting to Word, Writer, Excel or Calc uses LibreOffice, the same as the single-document export. See Adding Non-PDF Content for how indiPDF finds it.

31. Printing

Press Ctrl+P or select File → Print.
On Linux, the system print dialog opens directly (works in both native and Flatpak modes).
On macOS and Windows, a printer-picker dialog lets you choose a printer, set copies, and select pages.
Click Print.

All annotations are included in the printed output.

32. PDF Compression

Reduce PDF file size using Ghostscript.

Select Tools → Compress PDF.
Choose a quality preset:
- Screen (72 dpi) — Smallest size, best for screen viewing.
- eBook (150 dpi) — Good balance. Recommended for most uses.
- Printer (300 dpi) — High quality for printing.
- Prepress (300+ dpi) — Maximum quality.
Click Compress.

Requirements

Ghostscript must be installed. On macOS and Windows builds, it is bundled automatically. On Linux:

sudo apt install ghostscript (Debian/Ubuntu)
sudo dnf install ghostscript (Fedora)

The Flatpak version includes Ghostscript out of the box.

33. PDF/A Export (Archival)

Convert PDFs to ISO-standardized archival format for long-term preservation.

Select Tools → Export as PDF/A.
Choose a conformance level:
- PDF/A-1b — Most compatible. Widely supported.
- PDF/A-2b — Supports transparency and JPEG2000.
- PDF/A-3b — Allows embedded file attachments.
Click Export and choose a destination.

Requires Ghostscript (see Compression section for install instructions).

34. Encryption & Passwords

Password-protect your PDFs with AES-256 encryption.

Select Tools → Encrypt PDF.
Set a user password (required to open) and/or an owner password (required to change permissions).
Choose which permissions to allow: printing, copying, modification.
Click Encrypt.

Requires qpdf. Bundled automatically on macOS/Windows. On Linux: sudo apt install qpdf or sudo dnf install qpdf. The Flatpak version includes qpdf.

35. Security Scanning

indiPDF automatically scans PDFs for potentially dangerous elements when you open them.

What's Detected

Embedded JavaScript
Launch actions
XFA forms
Form submission URLs
Data import actions
Embedded executable files
Auto-open actions

Threats are categorized by severity (high, medium, low). You can choose to open the document with scripts, open a sanitized copy (active content stripped), or cancel.

Sanitization

Go to Tools → Sanitize PDF to strip all active content from a document while keeping form fields fillable.

36. Document Properties

View and edit PDF metadata:

Select File → Document Properties.
Edit the Title, Author, and Subject fields.
Click Save to apply.

37. Checking for Updates

indiPDF checks for new versions shortly after startup. If an update is available, a notification offers options to download or defer.

Manual Check

Go to Help → Check for Updates.

How to Update

Flatpak: flatpak update com.indomitusgroup.indipdf
APT: sudo apt update && sudo apt upgrade indipdf
DNF: sudo dnf upgrade indipdf
macOS / Windows: Download the latest installer from the indiPDF page.

38. Keyboard Shortcuts

Shortcut	Action
`Ctrl+O`	Open file
`Ctrl+S`	Save
`Ctrl+Shift+S`	Save As
`Ctrl+P`	Print
`Ctrl+W`	Close document
`Ctrl+F`	Find / Search
`Ctrl+G`	Find next
`Ctrl+Shift+G`	Find previous
`Ctrl+Z`	Undo
`Ctrl+Shift+Z` / `Ctrl+Y`	Redo
`Ctrl++`	Zoom in
`Ctrl+-`	Zoom out
`Ctrl+0`	Fit to width
`Ctrl+Shift+B`	Two-page (book) view
`Ctrl+Scroll`	Zoom in/out (10% per tick)
`Ctrl+R`	Rotate page
`Ctrl+M`	Toggle comment tool
`F9`	Toggle sidebar
`[` / `]`	Decrease / increase pen stroke width
`Delete`	Delete selected annotation
`Escape`	Switch to Select tool

39. Licensing

Free vs. Licensed

indiPDF is fully functional without a license. The only difference is that unlicensed copies add a small watermark to saved documents. A one-time purchase of $35 removes the watermark permanently.

Taking the Watermark Off Work You Already Did

If you evaluated indiPDF, saved real work, and then bought a licence, you do not have to do that work again. A licensed copy can take the watermark off documents it already stamped: Tools → Remove indiPDF Watermark.

It removes all of it — the mark on the page, the link that sits behind it, and the note left in the document’s properties. Save the document afterwards to keep the change.

On documents watermarked by version 2.2 or later, removal is exact. Files stamped by an earlier version carry nothing identifying the watermark, so indiPDF matches on the wording instead and tells you so before touching anything — a good match rather than a certain one. Keep a copy of the file first if it matters.

The menu item is greyed out without a licence, which is the whole point of it.

Activating a License

Go to Help → License Key.
Enter your license key.
Click Activate.

Validation is performed locally. No internet connection is required after activation.

Purchasing

Select Help → Buy indiPDF from within the application, or visit indomitusgroup.com/indipdf.

40. Installation

Linux — Flatpak (Recommended)

flatpak install flathub com.indomitusgroup.indipdf

The Flatpak bundles Ghostscript and qpdf so compression, encryption, and PDF/A export work out of the box.

Linux — Debian / Ubuntu / Mint (APT)

curl -fsSL https://downloads.indomitusgroup.com/indipdf/repos/deb/KEY.gpg | sudo gpg --dearmor -o /usr/share/keyrings/indipdf.gpg
echo "deb [signed-by=/usr/share/keyrings/indipdf.gpg] https://downloads.indomitusgroup.com/indipdf/repos/deb stable main" | sudo tee /etc/apt/sources.list.d/indipdf.list
sudo apt update && sudo apt install indipdf

Linux — Fedora / RHEL / CentOS (DNF)

sudo dnf config-manager --add-repo https://downloads.indomitusgroup.com/indipdf/repos/rpm/indipdf.repo
sudo dnf install indipdf

Linux — AppImage

Download the .AppImage from the indiPDF page, make it executable (chmod +x indiPDF_*.AppImage), and run it. No installation required.

Linux — Manual .deb / .rpm

Debian/Ubuntu: sudo dpkg -i indipdf_*.deb
Fedora/RHEL: sudo rpm -i indipdf-*.rpm

macOS

Download the .dmg universal binary (Apple Silicon + Intel) from the indiPDF page. Open the DMG and drag indiPDF to your Applications folder. Ghostscript and qpdf are bundled.

Windows

Download the MSI or NSIS installer from the indiPDF page. Run the installer and follow the prompts. Ghostscript and qpdf are bundled.

41. Platform Notes

Linux

File dialogs use xdg-desktop-portal for Flatpak compatibility.
Printing uses CUPS (lp / lpstat).
Scanning uses SANE (scanimage).
Theme detection reads GTK settings, XDG portal, and environment variables.

macOS

Universal binary runs natively on both Apple Silicon and Intel Macs.
Printing uses macOS's built-in CUPS subsystem.
Scanning via SANE requires Homebrew: brew install sane-backends.
File dialogs and theme detection use native Tauri/WKWebView integration.
First launch may require right-click → Open to bypass Gatekeeper (unless the app is notarized with an Apple Developer ID).

Windows

Printer enumeration uses the Win32 Spooler API. Printing uses the Windows shell printto verb via the default PDF viewer.
Scanning uses WIA (Windows Image Acquisition). Any WIA-compatible USB or network scanner is detected automatically.
Windows SmartScreen may warn on first run if the installer is not code-signed.

42. Tips & Tricks

Multiple documents: Open several PDFs in tabs and switch between them.
Quick tool switching: Press Escape to return to the Select tool.
Straight lines: Hold Shift while using the freehand tool to draw a straight line.
Precise placement: Zoom in for fine-grained annotation positioning.
Persistent settings: Your color, font, stroke width, and opacity choices are remembered across sessions.
One-click signatures: When you have a single saved signature, clicking the Signature tool places it instantly — no dialog needed.
Undo everything: Nearly every action can be undone with Ctrl+Z.

43. Troubleshooting

PDF won't open

Verify the file is a valid PDF by trying another viewer.
If prompted for a password, enter the correct password. Permission-only PDFs should open without a prompt.

Blank or white window on startup (Linux)

Some GPU drivers (especially NVIDIA) cause WebKitGTK to render a blank window. indiPDF sets WEBKIT_DISABLE_COMPOSITING_MODE=1 automatically, but if you still see issues, try launching with:

WEBKIT_DISABLE_DMABUF_RENDERER=1 indipdf

Slow or unresponsive with large scanned PDFs (Flatpak)

On some newer Linux systems, very large image-heavy documents — such as multi-page scans at high resolution — can render slowly or become unresponsive in the Flatpak build specifically: scrolling stutters, tools feel laggy, and freehand drawing may register only as short fragments, often getting worse after navigating between pages. This is caused by a performance and stability issue in the newer WebKitGTK rendering engine bundled with the Flatpak runtime — not by indiPDF itself. The same document on the same hardware works smoothly in the native builds, which use your system's WebKitGTK.

If you regularly work with large scanned PDFs and hit this, use the DEB or RPM package instead of the Flatpak (see Installation) — the native packages are not affected. Ordinary text-based PDFs are unaffected in every build, regardless of length.

Annotations not visible in other PDF readers

Use Save & Flatten to permanently embed annotations. A normal save also writes standard ISO 32000 annotation objects, which most modern readers support.

Freehand drawings appear rotated

This was fixed in version 1.3.1. If you encounter this, update to the latest version.

Ghostscript / qpdf not found (compression, encryption, PDF/A)

Flatpak: Both are bundled. If missing, reinstall: flatpak uninstall com.indomitusgroup.indipdf && flatpak install flathub com.indomitusgroup.indipdf
macOS / Windows: Both are bundled with the installer.
Linux (native): Install manually — sudo apt install ghostscript qpdf or sudo dnf install ghostscript qpdf.

Scanner not detected

Linux: Ensure SANE is installed and your scanner model is supported. Run scanimage -L in a terminal to check.
Flatpak: The Flatpak uses its own bundled SANE, which lacks the vendor driver backends (HP, Epson, Brother, …) many scanners require. If your scanner isn't detected, first make sure your system's SANE sees it (scanimage -L on the host), then grant the Flatpak access to it with flatpak override --user --talk-name=org.freedesktop.Flatpak com.indomitusgroup.indipdf and restart indiPDF. Requires indiPDF 2.0 or later — earlier versions ignore this permission. The override persists across reinstalls; remove it with flatpak override --user --reset com.indomitusgroup.indipdf.
macOS: Install SANE via brew install sane-backends.
Windows: Ensure your scanner is WIA-compatible and connected. Check Settings → Bluetooth & devices → Printers & scanners.

System LibreOffice not used for conversion (Flatpak)

If you export to Word (.docx), or add a legacy Office document (DOC, ODT, XLS, ODS, PPT/PPTX, ODP, RTF), and indiPDF falls back to its simpler built-in conversion even though you have LibreOffice installed, this is expected in the Flatpak build. For security, the Flatpak sandbox cannot see or launch programs installed on your host system, so a system LibreOffice (or OnlyOffice, or Microsoft Office) is invisible to it. Unlike the scanner case above, there is no flatpak override that enables it — the conversion runs entirely inside the sandbox.

You have two options:

Built-in conversion (no setup): DOCX, XLSX, CSV, TXT, and Markdown convert out of the box in the Flatpak. Word export also works built-in. The text comes through reliably; only complex page layouts are simplified.
Full LibreOffice fidelity: Use the native AppImage, DEB, or RPM build instead of the Flatpak (see Installation). These run outside the sandbox and use your system LibreOffice automatically — no configuration needed. If the AppImage opens to a blank white window, see Blank or white window on startup above for the one-line launch fix.

A document won't open, or opens mostly blank

A PDF contains an internal index recording where each piece of content lives. If that index is wrong — from an interrupted download, a faulty program that wrote the file, or damage in transit — readers cannot find content that is often still perfectly intact. The document may refuse to open, or open with pages blank or missing most of their text.

indiPDF can rebuild that index:

If a document won't open, indiPDF offers to repair a copy and open that instead.
If it opens but looks wrong, use Tools → Repair Document.

Your original file is never modified. The repaired version opens unsaved so you can check it before keeping it, and indiPDF reports how many pages were recovered — if some could not be, it says so rather than quietly giving you a shorter document.

Repair uses qpdf, bundled with the Flatpak, macOS and Windows builds. On a native Linux install you may need sudo apt install qpdf or sudo dnf install qpdf.

“This document requires Adobe Reader 8 or higher”

Some organisations — tax offices, municipalities, insurers — send forms built with XFA, a form format Adobe added on top of PDF. There are two kinds, and indiPDF tells you which one you have when you open the file.

Static or hybrid XFA: the fields are drawn on the pages and an ordinary PDF form sits alongside the XFA description. indiPDF offers to open that ordinary form layer, and the document then fills in and saves like any other.
Dynamic XFA: nothing is on the pages at all. The file contains one placeholder page — the “requires Adobe Reader 8 or higher” message you may have seen — and the form itself exists only as XML, assembled at open time by software only Adobe makes.

For a dynamic form, that placeholder genuinely is the whole document: no reader other than Adobe Acrobat Reader can show you the form, and there is nothing underneath for indiPDF to reveal. You can still open it here to read, annotate or print it. If you need to complete it, ask the sender whether they can supply an ordinary PDF form — many organisations keep one, and some have dropped XFA entirely, since neither browsers nor phones can open these files either.

Need More Help?

Visit our support page to report issues or request features, or send an email to Support Team.