Open PDF Studio

A free, open-source PDF editor and annotator for Windows, macOS, Linux, and Android.

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Open PDF Studio is a lightweight, native desktop application that provides professional-grade PDF annotation, markup, and editing tools without subscriptions, telemetry, or bloatware. Built with Tauri 2 and web technologies, it delivers a fast, modern experience with a Microsoft Office-style ribbon interface.

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Downloads, commit activity, and star growth for this active open-source project.

   

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Why Open PDF Studio?

Professional annotation, markup, measurement, redaction and page management — the tools that typical commercial PDF editors lock behind a subscription or a paid tier — are all included, free and fully open source. No subscriptions, no telemetry, no watermarks.

	Open PDF Studio	Typical commercial PDF editors
Price	Free & open source (LGPL-3.0)	Subscription or paid license
Annotations & markup	All included	Often a paid tier
Measurement tools	Included	Usually paid
Stamps, watermarks & redaction	Included	Usually paid
Page management	Included	Usually paid
Multi-tab editing	Included	Varies
Telemetry	None	Common
Platforms	Windows, macOS, Linux, Android	Varies (often fewer)

Features

Annotations & Markup (20+ Tools)

• Text markup: Highlight, underline, strikethrough
• Shapes: Rectangle, ellipse, polygon, cloud, cloud polyline, line, arrow, polyline
• Hatch fill patterns: Cross-hatch, diagonal, dots, and more for shape fills
• Freehand drawing: Pen tool with configurable color, width, and opacity
• Text annotations: Text box, callout with leader line, sticky notes with popup editing
• Stamps: 10 built-in stamps (Approved, Rejected, Draft, Confidential, Final, etc.)
• Images: Insert from file, paste from clipboard, or drag-and-drop, with non-destructive cropping
• Signatures: Draw multi-stroke signatures, save up to 5 for quick reuse
• Redaction: Mark areas and apply to permanently remove content

Measurement Tools

• Distance, area, and perimeter measurement
• Scale calibration dialog with mm, cm, m, inches, feet, and points
• Per-line scale override, with fallback to the document scale
• Quick scale: right-click a dimension line and type a value (e.g. "12.3m") to recalibrate
• Draggable dimension text and endpoints with live recalculation
• Object snapping to endpoints, midpoints, centers, and edges
• Angle snapping with configurable increments

PDF Compare

• Compare two PDF revisions in a dedicated compare tab, without leaving your workspace
• Side-by-side and overlay view modes with synchronized scrolling, panning, and zoom
• Automatic change detection classifies differences as added, removed, or modified
• Filterable change list with counts; click a change to jump straight to it
• Manual alignment offset (dx, dy, rotation) to line up drawings that shifted between revisions
• Page-pair navigation for multi-page documents

Symbol Palettes

• Drag-and-drop symbol libraries onto the page for repetitive markup
• Built-in libraries plus NEN 1414 and Dutch (NL) category sets
• Searchable, collapsible categories; enable or disable groups per project
• Create custom symbol groups saved with your preferences
• Dockable to either side of the canvas or floated freely

Quantities & Object Counting

• Count tool with named tally categories for on-drawing object counting (takeoff)
• Live quantities schedule that aggregates counts, lengths, and areas
• Grouping, sorting, filtering, subtotals, and grand totals
• Configurable columns, formatting, and table appearance
• Place the generated schedule back onto the page as a table

Screenshot

• Capture full page or a selected region as an image
• Copy to clipboard or save to file

Crop Margins

• Auto-detect and trim whitespace around page content

Text Editing

• Edit existing PDF text content inline
• Add new text annotations with font, size, and color control

Page Management

• Insert blank pages (standard or custom sizes)
• Delete, extract, and replace pages
• Reorder pages via drag-and-drop thumbnails
• Merge multiple PDFs into one
• Page rotation (90/180/270 degrees)

Watermarks & Headers/Footers

• Text and image watermarks with opacity, rotation, and position control
• Headers and footers with variables ({page}, {pages}, {date}, {time}, {filename})
• Apply to all pages or specific ranges

Forms

• Fill interactive PDF forms (AcroForms and XFA)
• Create text fields, checkboxes, and radio buttons
• JavaScript validation support

Printing

• Full print dialog with live preview
• Page range, subset (odd/even), reverse order, copies, and collation
• Scaling: fit to page, actual size, or custom percentage
• Print content: document only, markups only, or both
• Print as image option
• Virtual printer installation (Windows)

Export

• Export pages as PNG or JPEG (72, 150, 300, 600 DPI)
• Export as raster PDF
• Export/import annotations as XFDF

Find & Search

• Text search with match case and whole word options
• Highlight all matches with result count
• Navigate results with F3

Format & Styles

• 12 pre-defined style gallery for quick annotation styling
• Fill color, stroke color, line width, opacity, and border style
• Blend modes for annotation compositing
• Per-annotation-type default styles

Multi-Select & Alignment

• Select multiple annotations with rubber band or Ctrl+Click
• Shared property editing across selected annotations
• 6-point alignment (left, center, right, top, middle, bottom)
• Horizontal and vertical distribution
• Match size (width, height, or both)
• Flip horizontal/vertical and rotate selected annotations
• Z-order control (bring to front/back, forward/backward)

Object Snapping

• Snap to endpoints, midpoints, centers, and edges
• Snap to in-progress vertices while drawing polylines and measurements
• Configurable snap radius (3-30px)
• Angle snapping (1-90 degree increments)
• Optional grid overlay with grid snapping

Tool Palette

• Floating or dockable toolbar with all annotation tools
• Dock to left or right side of the canvas
• Quick access without switching ribbon tabs

PDF Viewing & Navigation

• High-quality native rendering via a multi-process PDFium worker pool — off the UI thread and crash-isolated, so a bad page never freezes or takes down the app
• Progressive tile rendering for very large CAD drawings: the page and its thumbnails fill in tile-by-tile across the worker pool instead of a seconds-long blank wait
• View modes: single page, continuous scroll, and book (two-page spread, page 1 on the right)
• Zoom: fit page, fit width, actual size, custom percentage, and cursor-anchored mouse-wheel zoom
• Page navigation: first, previous, next, last, go to page
• PDF/A compliance detection with read-only enforcement
• Digital signature validation panel

Left Panel (10 Tabs)

Thumbnails, Bookmarks, Annotations, Attachments, Digital Signatures, Layers, Form Fields, Named Destinations, Links, Tags

Bookmarks

• Create, edit, and delete bookmarks
• Hierarchical tree with expand/collapse
• Custom colors and text styling (bold, italic)

Document Management

• Multi-tab interface for multiple PDFs
• Session save/restore (named workspace snapshots)
• Open PDF from URL
• Bookmarked folder places for quick file access
• Recent files with pin/unpin
• Unsaved changes detection with save prompt
• Document properties dialog
• File locking to prevent external writes

Ribbon Interface

• Primary tabs: Home, Comment, Drawing, View, Organize, Help
• Contextual tabs: Format and Arrange appear automatically when annotations are selected

Customization

• 5 themes: Dark, Light, Blue, High Contrast, System (auto-detect)
• 39 languages including RTL support: Arabic, Bengali, Bulgarian, Catalan, Chinese, Croatian, Czech, Danish, Dutch, English, Finnish, French, German, Greek, Hebrew, Hindi, Hungarian, Indonesian, Italian, Japanese, Korean, Malay, Norwegian, Farsi (Persian), Polish, Portuguese, Romanian, Russian, Serbian, Slovak, Spanish, Swahili, Swedish, Tamil, Thai, Turkish, Ukrainian, Urdu, Vietnamese
• Configurable preferences dialog

Undo/Redo

• Up to 100 levels per document
• Covers annotations, page operations, watermarks, and text edits

Auto-Update

• Built-in update checker with download progress
• Skip version or remind later options
• Automatic installation and relaunch

Keyboard Shortcuts

Shortcut	Action
Ctrl+N	New document
Ctrl+O	Open file
Ctrl+S	Save
Ctrl+Shift+S	Save As
Ctrl+P	Print
Ctrl+Z	Undo
Ctrl+Y / Ctrl+Shift+Z	Redo
Ctrl+F	Find
F3	Find next
Ctrl+A	Select all annotations on page
Ctrl+C / Ctrl+V	Copy / Paste annotations
Delete	Delete selected annotation(s)
Ctrl+D	Document properties
Ctrl+W	Close active tab
V	Select tool
H	Hand tool
T	Text box tool
N	Sticky note tool
Ctrl+= / Ctrl+-	Zoom in / Zoom out
Ctrl+0	Actual size
Ctrl+1	Fit width
Ctrl+2	Fit page
F9	Toggle navigation panel
F11	Toggle annotations list
F12	Toggle properties panel
F1	Keyboard shortcuts
Arrow keys	Nudge annotation (1px, Shift for 10px)
Enter	Complete area/perimeter measurement

Installation

Windows

Download the latest .exe installer from Releases.

macOS

Download the latest .dmg (universal binary for Intel and Apple Silicon) from Releases.

Linux

Snap (Ubuntu App Center):

sudo snap install open-pdf-studio

Debian/Ubuntu (.deb):

sudo dpkg -i open-pdf-studio_*.deb

AppImage:

chmod +x open-pdf-studio_*.AppImage
./open-pdf-studio_*.AppImage

Android

Download the APK from Releases.

Building from Source

Prerequisites

• Node.js 20+
• Rust (stable)
• CMake and a C/C++ toolchain
• System dependencies:
  • Linux: libwebkit2gtk-4.1-dev libappindicator3-dev librsvg2-dev patchelf
  • macOS: Xcode Command Line Tools; universal release builds also need the aarch64-apple-darwin and x86_64-apple-darwin Rust targets
  • Windows: Visual Studio Build Tools with C++ workload

Build

cd open-pdf-studio
npm ci
npx tauri build

The build automatically downloads the pinned macOS PDFium runtime and verifies its SHA-256 checksum. Build artifacts are written to the workspace-level target/release/bundle/ directory, or target/universal-apple-darwin/release/bundle/ for a universal macOS build.

Development

cd open-pdf-studio
npm ci
npx tauri dev

Tech Stack

Layer	Technology
Desktop framework	Tauri 2 (Rust backend)
UI framework	SolidJS
Build tool	Vite
Page rendering	Multi-process PDFium worker pool, with progressive tiling for large drawings
Text layer & structure	PDF.js
PDF manipulation	pdf-lib

Contributing

Contributions are welcome. See CONTRIBUTING.md for the full guidelines.

In short: because the codebase moves quickly, a clear, well-described issue is usually more valuable than a code pull request — a precise description can be implemented against the current code before a branch would go stale.

Symbol libraries and content — pull requests very welcome

Content is the exception to "prefer issues over PRs". We want every symbol library in the world. Symbol sets, hatch patterns, and other reusable content don't go stale the way code does, so content pull requests are actively encouraged — bring the standards and libraries from your country, industry, and discipline. Symbols are organised by industry (e.g. AEC) and country (e.g. NL), and localisation will keep expanding, so libraries for any region are welcome.

We're looking for a content & extensions maintainer

We are looking for someone to own and maintain the extensions and the content repository — curating incoming symbol libraries and content contributions, and keeping the ecosystem organised as it grows. If that sounds like you, please open an issue to introduce yourself.

License

Open PDF Studio is licensed under the GNU Lesser General Public License v3.0.

PDF.js is licensed under the Apache License 2.0. pdf-lib is licensed under the MIT License. PDFium is licensed under the BSD 3-Clause License.