Open a .docx without Microsoft Office. LeanDoc shows the document as pages, never runs macros, and never fetches anything the document points to. MIT licensed, no telemetry. The 0.2.0 Windows download is a 950 KiB ZIP.
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Read the document, not the office suite.
LeanDoc is a read-only desktop viewer for Word documents. It opens a .docx
as pages, never runs anything inside it, never fetches anything the document
points to, and has one button that hands the file to a real editor.
The Linux build (GTK 4 and WebKitGTK 6.0) showing a sample report with headings, a list, a table, a footnote, and an Arabic paragraph. The document and the capture script are in docs/images/screenshot-source/.
Windows 11 24H2 removed WordPad, and the Explorer preview for .docx files
needs Microsoft Office. A Windows PC without Office now has no built-in way to
read the document someone just emailed.
People who do have Word often only want to read. Word takes seconds to start and is built for writing. LeanDoc is built for reading: it opens the file, shows it, and gets out of the way. It is MIT licensed, like its siblings LeanMark, a Markdown viewer with offline Mermaid diagrams, and LeanRows, a large CSV viewer for files too big for Excel.
On Windows:
winget install abooodbah.LeanDocWindows, Linux (.deb), and macOS builds are all on the
Releases page.
LeanDoc is also in the Microsoft Store. The Store build is signed by Microsoft, so Windows installs it without the SmartScreen warning that the unsigned GitHub ZIP can show. It can also be installed from the Store with winget:
winget install --id 9NSM04BJL6F6 --source msstorescoop bucket add lean https://github.com/abooodbah/scoop-bucket
scoop install lean/leandocFrom an administrator PowerShell:
choco install leandoc -yThe LeanDoc package installs the portable Windows ZIP from the GitHub release, checks its SHA-256, and adds a Start menu shortcut and a command-line shim. To move an existing Chocolatey installation to the newest release:
choco upgrade leandoc -yA new version reaches Chocolatey once its moderators have approved the package, which can take a few days after the GitHub release.
brew install --cask abooodbah/tap/leandocThe macOS build is not notarized by Apple, so macOS blocks the first launch. Open LeanDoc once, then choose Open Anyway under System Settings > Privacy & Security. Later launches open normally.
LeanDoc for Android is in a closed test on Google Play before its public release. To try it:
- Join the Lean Apps testers group with the Google account you use on your phone.
- On your phone, open the LeanDoc tester page, tap Become a tester, then install LeanDoc from Google Play.
If the tester page says the app is not available yet, Google is still reviewing the test; try again a day later. Google asks testers to keep the app installed for 14 days. The APK is also attached to each Android release.
| Operating system | Architecture | v0.2.0 artifact | Runtime |
|---|---|---|---|
| Windows 10 / 11 | x64 | LeanDoc-v0.2.0-windows-x64.zip | Microsoft Edge WebView2 Runtime |
| Ubuntu 24.04 and compatible | x86-64 | LeanDoc-v0.2.0-linux-x86_64.deb | GTK 4 and WebKitGTK 6.0 |
| macOS 12 or later | Intel and Apple silicon | LeanDoc-v0.2.0-macos-universal-preview.zip | Preview, system WKWebView |
Each artifact has an adjacent .sha256 sidecar on the
v0.2.0 release.
The macOS preview also has a .metadata.json file that records how it was
signed. Windows ARM64 and Linux ARM64 are not part of this release.
Important
The Windows executable is unsigned. The macOS preview bundle is ad-hoc signed with the hardened-runtime flag but is not Developer ID signed or notarized. Windows SmartScreen or macOS Gatekeeper may therefore ask for an explicit trust decision. Official project binaries are limited to assets attached to this repository's GitHub Releases. The published checksum proves byte identity with the release asset; it does not replace platform code signing.
Check a download against its sidecar before you run it:
Get-FileHash .\LeanDoc-v0.2.0-windows-x64.zip -Algorithm SHA256sha256sum -c LeanDoc-v0.2.0-linux-x86_64.deb.sha256The extracted ZIP is portable. LeanDoc.exe, WebView2Loader.dll, and the
assets folder must stay together. Open documents from the app, drop them on
the window, or pass them on the command line. Documents open as tabs in one
window, and a later launch hands its files to that window.
The optional per-user installer adds LeanDoc to the Start menu, to Open With,
and to Default Apps for .docx, .dotx, .docm, .dotm, .doc, .rtf, and
.odt. LeanDoc shows the first four as pages; .doc, .rtf, and .odt open to
a page with the button to your editor. It makes LeanDoc the default only for a
type that has no default app yet. It never changes a default you or your
organisation already chose.
powershell.exe -NoProfile -ExecutionPolicy Bypass -File .\installer\install.ps1 -ValidateOnly
powershell.exe -NoProfile -ExecutionPolicy Bypass -File .\installer\install.ps1It copies LeanDoc to %LOCALAPPDATA%\Programs\LeanDoc. Uninstalling removes
LeanDoc's files, its Start menu and Open With entries, its WebView2 data folder
under %LOCALAPPDATA%\LeanDoc, and restores any default it set. Uninstall in
Settings or with:
powershell.exe -NoProfile -ExecutionPolicy Bypass -File "$env:LOCALAPPDATA\Programs\LeanDoc\uninstall.ps1"The installer notes list exactly what it writes.
tools\leandoc-inspect.exe in the ZIP prints the core's report for a file; it
is not put on PATH.
The Debian package declares its GTK 4 and WebKitGTK 6.0 dependencies, so APT resolves them:
sudo apt install ./LeanDoc-v0.2.0-linux-x86_64.debIt installs /usr/bin/leandoc, a desktop entry, AppStream metadata, the icon,
and the reader assets. It offers LeanDoc for Word documents without replacing
your default app. A later launch opens its files as tabs of the running
window.
The ZIP holds LeanDoc.app with Intel and Apple silicon slices. Move it to
/Applications or another folder. Finder offers LeanDoc as a viewer for the
same seven extensions, and documents use the system's window tabs.
Because the preview is not notarized, Gatekeeper may block the first launch. macOS records an explicit approval under System Settings > Privacy & Security. Environments that require a notarized app are not supported by this release.
.docx,.dotx,.docm, and.dotmfiles, including Strict OOXML.- Paragraph and character styles with their inheritance, theme fonts and colours, and multi-level numbering.
- Bullets in Symbol and Wingdings fonts, mapped to the characters they show in Word.
- Tables with merged cells, borders, and shading.
- Pictures stored as PNG, JPEG, GIF, or BMP.
- Headers and footers, footnotes and endnotes, links, and page and section breaks.
- Right-to-left text: Arabic paragraphs, numbered lists, and mirrored tables, and Arabic and English in one paragraph.
Page view is the default. Reading view reflows the text to the window and is one click (or Ctrl+Shift+V) away. Zoom runs from 50 to 300 percent, with fit width. A navigation pane lists the headings, find searches the whole document, and five themes (System, Light, Dark, Dim, and Dusk, as in LeanMark) colour LeanDoc's window. The page stays white like paper, or, with the page colour setting, takes the theme's colours; on a dark theme the document's own colours are turned to the theme so its text stays readable. The settings button (Ctrl+/ or F1) holds the theme, the view, the page colour, the zoom, and the list of every keyboard shortcut.
.doc, password-protected documents, .rtf, .odt, and files that are not
Word documents get a plain page that says what the file is, with the
open-in-editor button.
LeanDoc does not pretend. When a document holds content it does not display, a quiet bar above the page says so, with counts, and offers the editor:
The Linux build with a sample draft that holds a text box and tracked changes. The details list is open.
- The first sentence names what is not displayed: text boxes, equations, charts, SmartArt, shapes, OLE objects, ActiveX controls, and imported content.
- The second sentence names what LeanDoc handled for you: tracked changes (shown as accepted), comments (hidden), macros (not run), and remote templates, images, and fields (not fetched).
- Details lists every feature and its count. The bar can be collapsed for a tab. It is never a modal, and it never hides itself for good.
How well LeanDoc renders is measured against Word with a fixed list of 30 documents and a five-point rubric in docs/FIDELITY.md. The score is not yet recorded.
- Charts, SmartArt, and most text boxes are not displayed. Most equations display; the forms LeanDoc cannot draw show an "[Equation]" marker. The fidelity bar names everything that is not displayed and offers the editor.
.doc(Word 97 to 2003) files are not rendered. They get a fallback page.- LeanDoc lays out pages itself, starting from the page starts Word saved in the file and the document's explicit breaks, so page numbers can differ from Word's.
- No printing.
- No comments panel. Comments are hidden and counted.
- Links in headers, footers, footnotes, and endnotes are plain text.
- No editing or saving, ever. The macOS build is a preview and is not notarized.
The full list is in the 0.1.0 release notes.
| Action | Windows / Linux | macOS |
|---|---|---|
| Open a document | Ctrl+O | Command+O |
| Find | Ctrl+F | Command+F |
| Next / previous match | Enter / Shift+Enter or F3 / Shift+F3 | Enter / Shift+Enter or F3 / Shift+F3 |
| Leave find | Escape | Escape |
| Zoom in / out / reset | Ctrl++ / Ctrl+- / Ctrl+0 | Command++ / Command+- / Command+0 |
| Switch page and reading view | Ctrl+Shift+V | Command+Shift+V |
| Cycle the theme | Ctrl+Shift+T | Command+Shift+T |
| Settings and shortcuts | Ctrl+/ or F1 | Command+/ or F1 |
| Close the settings panel | Escape | Escape |
| Open in the editor | Ctrl+Shift+E | Command+Shift+E |
| Copy all text | Ctrl+Shift+C | Command+Shift+C |
| Reload from disk | F5 or Ctrl+R | F5 or Command+R |
| Next / previous tab | Ctrl+Tab / Ctrl+Shift+Tab | Window menu |
| Go to tab 1 to 8 / last tab | Ctrl+1 to Ctrl+8 / Ctrl+9 | Window menu |
| Close tab | Ctrl+W | Window menu |
The Open in ... button names the editor LeanDoc found when it started, in this order:
- Microsoft Word.
- LibreOffice.
- Pages (macOS only).
- The system's default app for the document's file type, when that is not LeanDoc.
- Word for the web in your browser. It cannot receive the file, so LeanDoc says the file must be uploaded there.
The editor starts with an argument list, never through a shell.
These are facts about what LeanDoc's code does. They are not a guarantee about the web runtime the operating system provides.
- No macros run. LeanDoc has no macro engine, and
vbaProject.binnever reaches the reader. - Nothing is fetched. Remote templates, linked images, and
INCLUDEPICTURE,INCLUDETEXT,LINK, andDDEfields are removed or keep only their saved result. The reader's Content Security Policy allows fetches only from LeanDoc's own app origin. - The reader never sees the original file. A portable C++ core writes a new package that holds only allow-listed parts: the text, styles, numbering, notes, headers, footers, and pictures. ActiveX and OLE payloads, embedded fonts, imported HTML, and external relationships other than web and mail links are left out.
- DTDs are refused. Any XML part that declares a document type or an entity fails before parsing, so entity expansion and external entities never happen.
- The ZIP is bounded. At most 256 MiB on disk, 4,096 entries, 64 MiB per part, 512 MiB in total, a compression-ratio limit, an XML depth limit, and no unsafe or duplicate entry names. Declared sizes are not trusted.
- Links leave only after a click. Web and mail links open in your browser or mail app only after you click them. Mail links keep only the address, subject, body, cc, and bcc. Nothing navigates inside the reader, and new windows, downloads, and permission requests are refused. The right-click menu inside the document offers no download or open-link items.
Vulnerability reports follow SECURITY.md.
LeanDoc's own code makes no network requests. It has no telemetry, no
update check, and no account. Outside the documents you open, it writes only
its settings: theme, view, page colour, and up to 10 recent files, in
HKCU\Software\LeanDoc on Windows, $XDG_CONFIG_HOME/leandoc/settings.ini
on Linux, and the app's defaults on macOS. Windows also keeps a WebView2
profile folder under %LOCALAPPDATA%\LeanDoc.
The page is drawn by the system web runtime: WebView2 on Windows, WebKitGTK on Linux, and WKWebView on macOS. That runtime belongs to the operating system and may contact its vendor on its own. LeanMark observed this with WebView2 on Windows; LeanDoc has not been measured on that point yet.
A link you click opens in your browser or mail app, and Open Word for the web opens a web page; those requests are made by those apps after your click.
flowchart LR
File[Local .docx] --> Core[Portable C++ core<br>miniz + pugixml]
Core -->|sanitized package<br>and JSON report| Host{Native host}
Host -->|Win32| W[WebView2]
Host -->|GTK 4| L[WebKitGTK 6.0]
Host -->|AppKit| M[WKWebView]
W --> Reader[Shared offline reader<br>docx-preview]
L --> Reader
M --> Reader
The core reads the file within fixed limits, classifies it, checks the ZIP and the XML, counts every feature for the fidelity bar, builds the outline, and writes the sanitized package. The native hosts own files, dialogs, tabs, settings, links, the editor button, and the web runtime's rules. The reader is one HTML, CSS, and JavaScript page shared by all three hosts; it lays out the sanitized package with a pinned copy of docx-preview. The decision is recorded in ADR 0001, and the hosts are described in docs/architecture/hosts.md.
Package sizes of the published v0.1.0 release assets. The system web runtime is part of the operating system and is not counted; it uses its own memory and disk.
| Package | Download | Unpacked |
|---|---|---|
| Windows ZIP | 907 KiB (928,322 bytes) | 1.76 MiB in 23 files (1,844,954 bytes) |
Linux .deb |
568 KiB (581,680 bytes) | 1.09 MiB installed (1,144,059 bytes) |
| macOS universal ZIP | 750 KiB (767,584 bytes) | 1.64 MiB in 29 files (1,720,373 bytes) |
Sizes are from the v0.1.0 release files, read on 2026-10-20. In 0.1.4 the
reader's two scripts and its style sheet are 106,112 bytes larger than in
0.1.0, and the core changed; in 0.2.0 the reader's page, scripts, and style
sheet are 39,855 bytes larger than in 0.1.4. The 0.2.0 release files are
972,464 bytes (Windows ZIP), 625,478 bytes (Linux .deb), and 811,831 bytes
(macOS ZIP), as the GitHub release lists them on 2026-11-07; their unpacked
sizes have not been measured again.
Measured figures will be added after a run on a reference Windows machine; the method is in tests/owner/README.md.
Every build needs CMake 3.22 or newer and Node.js 20 or newer. Node.js only stages the pinned reader packages and fonts at build time; LeanDoc does not run it. Install them first:
npm ci --ignore-scripts --no-audit --no-fundRequirements: Visual Studio 2022 or newer with the C++ workload, and the
Microsoft Edge WebView2 Runtime. scripts/build.ps1 downloads the pinned
WebView2 SDK and checks its SHA-256.
.\scripts\build.ps1 -Configuration Release -Platform x64
.\tests\Test-LeanDoc.ps1 -DistPath .\dist -Smoke -Runtime
.\scripts\package-release.ps1 -Version 0.2.0 -Platform x64Requirements on Ubuntu 24.04:
sudo apt install build-essential cmake ninja-build pkg-config \
libgtk-4-dev libwebkitgtk-6.0-dev
cmake -S . -B build/linux -G Ninja -DCMAKE_BUILD_TYPE=Release \
-DBUILD_TESTING=ON -DLEANDOC_ENABLE_GUI_TESTS=ON
cmake --build build/linux
dbus-run-session -- ctest --test-dir build/linux --output-on-failure
bash scripts/package-linux.sh --version 0.2.0Requirements: macOS 12 or later and Xcode or its command-line tools.
cmake -S . -B build/macos -G Xcode -DCMAKE_OSX_ARCHITECTURES="arm64;x86_64" -DBUILD_TESTING=ON
cmake --build build/macos --config Release
ctest --test-dir build/macos -C Release --output-on-failure
cmake --build build/macos --config Release --target package_macosDeveloper ID signing and notarization need credentials and protected release automation, and the public CI build does not simulate them.
src/core/: the portable C++ core.src/core/DocCore.his its contract.tools/inspect/:leandoc-inspect, the core on the command line.assets/: the shared reader page, styles, and scripts.src/windows/,src/linux/,macos/: the Win32 and WebView2, GTK and WebKitGTK, and AppKit and WKWebView hosts.installer/: the optional per-user Windows install and uninstall scripts.packaging/: Linux desktop metadata and winget manifests.tests/: core, reader, host, package, corpus, and owner measurement checks.site/: the dependency-free GitHub Pages site.docs/: the specification, decisions, release notes, and the fidelity list.
Rendering reports are welcome, especially for documents that look different
from Word. Never attach a private document: make a small file that shows the
problem, or describe it with the output of leandoc-inspect, which prints
the file's kind, feature counts, and headings. Use the
issue forms, and see
CONTRIBUTING.md, ROADMAP.md, and
CHANGELOG.md.
LeanDoc is the third of a small family of read-only viewers with the same look, the same plain words, and the same MIT licence.
- LeanMark: read Markdown and Mermaid diagrams offline without opening an IDE, on Windows, Linux, and macOS.
- LeanRows: open very large CSV, log, and JSON Lines files on Windows without loading them into memory.
This program will not transfer any information to other networked systems unless specifically requested by the user or the person installing or operating it.
LeanDoc's own code makes no network requests. It has no telemetry, no update check, and no account, and it never fetches anything a document points to: remote templates, linked images, and include fields are removed or keep only their saved result. A link you click opens in your browser or mail app, and Open Word for the web opens a web page in your browser; those requests are made by those apps after your click.
The page is drawn by a web runtime that is not part of LeanDoc: on Windows, the Microsoft Edge WebView2 Runtime, a Microsoft component that is installed and updated separately; WebKitGTK on Linux; and WKWebView on macOS. That runtime may contact its vendor on its own, under its vendor's terms. Privacy says what has been observed so far.
- Windows, installed with
installer\install.ps1: Settings > Apps > Installed apps > LeanDoc, or the installeduninstall.ps1, as described in Package use and the installer notes. - Windows, portable ZIP: delete the extracted folder. The settings key
HKCU\Software\LeanDocand the WebView2 folder%LOCALAPPDATA%\LeanDocstay until you delete them. - Windows, through Chocolatey:
choco uninstall leandoc, from an administrator shell. - Linux:
sudo apt remove leandoc. Your settings file$XDG_CONFIG_HOME/leandoc/settings.inistays until you delete it. - macOS: move
LeanDoc.appto the Trash.
LeanDoc is free to use, modify, and redistribute under the MIT License. Bundled components keep their own licences, listed in THIRD_PARTY_NOTICES.md.