indiPDF Documentation

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.

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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.

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3. Opening 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.

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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.

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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

Page Navigation

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

Searching

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

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6. Text Markup (Highlight, Underline, Strikethrough)

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

Applying Markup

1. Select the desired tool — Highlight, Underline, or Strikethrough — from the toolbar.
2. Click and drag across the text you want to mark up.
3. 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

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

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

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7. Text Annotations

Add free-form text boxes anywhere on your PDF.

Adding Text

1. Select the Text tool from the toolbar.
2. Click anywhere on the page.
3. Start typing. The text box expands as you type.
4. 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.

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8. Comments

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

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

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

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9. Link Annotations

Add clickable hyperlinks to your PDF.

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

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

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10. Drawing & Shapes

Freehand Drawing

1. Select the Draw (freehand) tool.
2. Choose a color and stroke width from the toolbar. Stroke width ranges from 1 to 12 pt.
3. Click and drag to draw. Hold Shift to draw a straight line from the starting point.
4. 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.

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11. Signatures

Create and apply digital signatures to your documents.

Creating a Signature

Select the Signature tool. The signature dialog offers three 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.
• 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.

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12. 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, 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.

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13. Images

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

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14. 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.

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15. OCR (Text Recognition)

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

Requirements

OCR requires Tesseract:

• Ubuntu / Debian: sudo apt install tesseract-ocr
• Fedora: sudo dnf install tesseract
• macOS: brew install tesseract
• Windows: Download from UB Mannheim

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

Running OCR

1. Open a scanned or image-based PDF.
2. Go to Tools → OCR.
3. Choose the language(s) for recognition.
4. Select pages to process (all, current, or custom range).
5. Click Start OCR.

How It Works

indiPDF creates editable text annotations over the recognized text. The original scanned image is preserved. You can correct recognition errors by editing the text, then Save & Flatten to produce a final searchable PDF.

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16. 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

1. Connect and power on your scanner.
2. Go to Tools → Scan.
3. Select your scanner from the dropdown.
4. Choose settings — source (flatbed/ADF), resolution (150–600 DPI), and color mode.
5. Click Scan. Repeat for additional pages.
6. 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.

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17. 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, PPTX, PPT, ODP (requires LibreOffice or OnlyOffice)
• Text Files: TXT, RTF, Markdown

How to Add

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

Office Document Conversion

Office document import requires LibreOffice or OnlyOffice. Install with:

• Ubuntu / Debian: sudo apt install libreoffice
• Fedora: sudo dnf install libreoffice
• macOS: brew install --cask libreoffice
• Windows: Download from libreoffice.org

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18. Page Management

Rotating Pages

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

Reordering Pages

Open the sidebar (F9) and drag-and-drop thumbnails to reorder pages.

Deleting Pages

• Single page: Right-click a thumbnail and select Delete Page.
• Batch delete: Ctrl+Click to select individual pages or Shift+Click to select a range. 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 to append pages from another PDF.

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19. Crop & Trim

Crop pages visually, like an image editor.

1. Go to Tools → Crop / Trim.
2. A crop overlay appears on the current page with eight resize handles and a dimmed exterior.
3. Drag the handles to define the visible area. Drag the interior to move the crop rectangle.
4. 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.

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20. Splitting & Merging

Merging PDFs

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

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

Splitting PDFs

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

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21. Exporting

Export as Images

1. Select File → Export (or click Export in the toolbar).
2. Choose the format: PNG, JPEG, or WebP.
3. Select pages and resolution/quality.
4. Click Export and select a destination folder.

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

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22. Printing

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

All annotations are included in the printed output.

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23. PDF Compression

Reduce PDF file size using Ghostscript.

1. Select Tools → Compress PDF.
2. 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.
3. 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.

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24. PDF/A Export (Archival)

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

1. Select Tools → Export as PDF/A.
2. 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.
3. Click Export and choose a destination.

Requires Ghostscript (see Compression section for install instructions).

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25. Encryption & Passwords

Password-protect your PDFs with AES-256 encryption.

1. Select Tools → Encrypt PDF.
2. Set a user password (required to open) and/or an owner password (required to change permissions).
3. Choose which permissions to allow: printing, copying, modification.
4. 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.

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26. 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.

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27. Document Properties

View and edit PDF metadata:

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

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28. 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.

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29. Keyboard Shortcuts

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30. 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.

Activating a License

1. Go to Help → License Key.
2. Enter your license key.
3. 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.

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31. 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.

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32. 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.

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33. 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.

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34. 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

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.
• macOS: Install SANE via brew install sane-backends.
• Windows: Ensure your scanner is WIA-compatible and connected. Check Settings → Bluetooth & devices → Printers & scanners.

Need More Help?

Visit our bug report page to report issues or request features.

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