TorReader PDF

A free, portable PDF reader and editor for Windows and Linux, built for people who work with large technical documents — drawing sets, tender packages, scanned reports — often on machines where installing software is awkward or not permitted.

No installer, no account, no upload, no internet required. A 300-page A1 CAD set opens in one to two seconds and scrolls without freezing: pages render in short interruptible slices backed by a memory + disk cache, and off-screen pages are evicted so RAM stays flat.

✨ What's new in 2.4

• New interface — high-contrast light and dark themes, consistent borders and selection states, and a neutral desk so the page edge is always visible.
• OCR for scanned documents — 10 languages. Vietnamese, English, Chinese (Simplified and Traditional), Japanese, Korean, French, Russian, Portuguese, Spanish. Bundled in the app, fully offline, and your file is never modified — the recognised text lives in memory only.
• Select, find and copy text — in PDFs and in scans. Character-level selection across lines and pages, double-click for a word, triple-click for a line. Search ignores diacritics by default, so MAT also finds MẶT. Results scroll straight to the match.
• Links work — internal links jump and briefly outline the target; external links show the full address and ask before opening.
• Faster — one shared page cache means a page is parsed once instead of several times.

Full notes: RELEASE_NOTES_2.4.md

More screenshots (viewer, dark mode, markup, search, OCR, merge)

⬇ Download

Platform	Install
Windows (x64)	TorReaderPDF-2.4.0-win64.zip — unzip & run TorReader.exe
Ubuntu / Debian (APT)	sudo mkdir -p /etc/apt/keyrings sudo curl -fsSL https://torreader.cloud/apt/torreader-archive-keyring.gpg -o /etc/apt/keyrings/torreader.gpg echo "deb [signed-by=/etc/apt/keyrings/torreader.gpg] https://torreader.cloud/apt stable main" | sudo tee /etc/apt/sources.list.d/torreader.list sudo apt update && sudo apt install torreader
Ubuntu / Debian (.deb)	sudo apt install ./torreader_2.4.0_amd64.deb
Arch Linux	yay -S torreader-bin (pending publication on AUR)
Any distro (AppImage)	TorReaderPDF-2.4.0-x86_64.AppImage — chmod +x & run (glibc 2.35+, requires system OpenGL)

Ships a freedesktop .desktop file and AppStream metadata, so it appears in your application menu and in "Open with" for PDFs.

🔐 Only two places publish TorReader PDF: this repository's Releases and torreader.cloud. Anything else is not ours — we have seen this project's name and description reused to push generic Application-x.y.zip archives on third-party sites. Two checks settle it: the link must be on github.com/FelixNgH/... or torreader.cloud, and the file name carries the product name and version (TorReaderPDF-2.4.0-win64.zip), never a bare setup.exe. Found a copy elsewhere? Open an issue.

Features

Fast viewer	Memory-mapped loading; 900MB files in 1–2s. Progressive interruptible rendering, two-layer cache, RAM-efficient continuous scroll, sharp at every zoom with mixed page sizes (A4 + A0–A3 in one file).
OCR	10 languages, bundled and offline. Recognised text is searchable, selectable and copyable; the file on disk is untouched.
Text	Character-level select, diacritic-insensitive find, copy. Works the same in scans after OCR.
Merge	Combines files keeping every bookmark, remapped to new page numbers — most free tools drop them.
Split / Extract / Insert	Split by page count or size; pull out any range; right-click a thumbnail to insert pages from another PDF, with bookmarks renumbered.
Sign	PKCS#7 detached, SHA-256, your own .pfx/.p12. Optional visible stamp placed by dragging.
Markup	Line, arrow, rectangle, ellipse, cloud, text box, sticky note, freehand, highlight. Colour, width and fill controls; select, move, undo/redo. Correct on rotated pages.
Translate	Alt+drag over text to translate in place, cached locally.
Pages & bookmarks	Delete, reorder, rotate; reorder bookmarks.
Safe save	Edits apply to an in-memory working copy; your original is overwritten only on Ctrl+S.

Dark mode throughout, and full keyboard shortcuts — press F1 in-app for the list.

How it compares

An objective look at 24 PDF apps — paid suites, open-source desktop viewers, self-hosted toolkits and web tools — across twelve everyday jobs. Sorted A–Z within each group; TorReader PDF is listed in its category, not on a pedestal.

Full comparison table — 24 tools × 12 jobs (click to expand)

Tool	Free	OSS	Port	Off	CAD	Merge	Split	Sign	Mark	Tr	Lnx	OCR
Commercial
ABBYY FineReader PDF	○	○	○	●	◐	●	●	●	●	○	◐	●
Adobe Acrobat Pro	○	○	○	●	◐	●	●	●	●	○	○	●
Bluebeam Revu	○	○	○	●	●	●	◐	●	●	○	○	●
Foxit PDF Editor	○	○	○	●	◐	●	●	●	●	○	◐	●
Kofax Power PDF	○	○	○	●	◐	●	●	●	●	○	◐	●
Nitro PDF Pro	○	○	○	●	◐	●	●	●	●	○	○	●
PDF-XChange Editor	◐	○	◐	●	●	●	●	●	●	○	○	●
Wondershare PDFelement	○	○	○	●	◐	●	●	●	●	◐	◐	●
Open-source
Evince / GNOME	●	●	○	●	◐	○	○	○	◐	○	◐	○
MuPDF	●	●	●	●	●	◐	◐	○	○	○	●	○
Okular (KDE)	●	●	◐	●	◐	○	○	◐	●	○	●	○
Qoppa Studio Viewer	●	○	○	●	◐	○	○	◐	●	○	●	○
Sumatra PDF	●	●	●	●	●	○	○	○	○	○	○	○
TorReader PDF	●	●	●	●	●	●	●	●	●	●	●	●
Xodo PDF	●	○	○	◐	◐	●	●	●	●	○	◐	◐
Self-hosted
PDF Arranger	●	●	◐	●	○	●	●	○	○	○	◐	○
pdfcpu	●	●	●	●	◐	●	●	◐	○	○	●	○
PDFsam Basic	●	●	◐	●	◐	●	●	○	○	○	●	○
Stirling-PDF	●	●	◐	●	◐	●	●	●	◐	○	●	●
Web
Chrome / Edge	●	◐	○	●	◐	○	○	○	◐	○	●	○
iLovePDF	◐	○	○	○	◐	●	●	●	◐	○	●	◐
PDF24 Tools	●	○	◐	◐	◐	●	●	●	◐	○	◐	●
Sejda	◐	○	○	◐	◐	●	●	●	●	○	●	◐
Smallpdf	◐	○	○	○	◐	●	●	●	◐	○	●	◐

_{Port = portable · Off = works offline · CAD = opens large CAD/A0 · Mark = markup · Tr = translate · Lnx = Windows + Linux.
● full · ◐ partial, limited or paid-tier only · ○ not available. Positioning as of 2026 — feature sets vary by version and licence tier; verify the current release before deciding. Source data: docs/compare_matrix.csv.}

FAQ

Is it free? Yes — free and open-source (MIT). No ads, no account, no watermark.

Do I need to install it? No. Unzip and run on Windows; chmod +x the AppImage on Linux.

Does it work offline? Yes, including OCR. Only the optional translate feature calls an online service, and only when you use it.

Can it merge without losing bookmarks? Yes — merging and inserting keep every bookmark and remap it to the new page numbers.

What does OCR do? It turns a scanned page into text you can search, select and copy — 10 languages, entirely offline, and your file is never modified. Table structure recognition is on the roadmap.

A free alternative to Adobe Acrobat, PDFsam or Foxit? For viewing, OCR, merging, splitting, extracting, inserting, signing and translating — yes, in one lightweight portable app.

Building from source

Requirements: CMake ≥ 3.25 · Qt 6 (Core, Widgets, Gui, Concurrent, PrintSupport, OpenGL, OpenGLWidgets, Network) · QPDF ≥ 11 · PDFium prebuilt from bblanchon/pdfium-binaries extracted into third_party/pdfium/ · optional OpenSSL (enables Sign PDF) · optional Tesseract (enables OCR). Optional dependencies are skipped cleanly when absent.

# Windows — Visual Studio Build Tools 2022 + vcpkg
vcpkg install qpdf openssl
cmake -B build -DCMAKE_TOOLCHAIN_FILE=C:/vcpkg/scripts/buildsystems/vcpkg.cmake
cmake --build build --config Release      # -> build/bin/Release/TorReader.exe

# Debian / Ubuntu
sudo apt install cmake qt6-base-dev libqt6opengl6-dev libqt6openglwidgets6 \
                 libqpdf-dev liblcms2-dev libssl-dev libtesseract-dev
cmake -B build && cmake --build build -j$(nproc)   # -> build/bin/TorReader

Architecture

• Rendering & structural editing — PDFium (BSD 3-Clause): merge, split, insert, extract, reorder, rotate.
• Bookmarks & compression — QPDF (Apache-2.0), lossless object-stream compression on save.
• OCR — Tesseract (Apache-2.0); recognised text is inserted as invisible text objects into the in-memory document only.
• UI — Qt 6 Widgets + OpenGL (PdfGpuView single page, ContinuousView scroll strip).
• All FPDF_* calls are serialized behind a global mutex — PDFium is not thread-safe.

See THIRD_PARTY_NOTICES.md for the full dependency list and licences.

License

MIT for TorReader PDF's own source (LICENSE); third-party dependencies keep theirs.

Author

Felix Nguyen Huy (@FelixNgH) · torreader.cloud · BIMServer.cloud — BIM infrastructure for architecture firms · @FelixNgHuy

Issues and pull requests welcome.