Your library has a fast lane now.
Rust underneath, a calm page on top. Kitab never makes you wait.
A desktop reader for PDF, books and Markdown, written in Rust and drawn on the GPU with GPUI. MuPDF renders the pages. There is no browser engine inside.
A t21 dev project, by TriptoAfsin, from the team behind Turbo Reader.
Get the latest version from Releases.
| System | Download |
|---|---|
| Windows 10 and 11 (Intel, AMD) | Kitab_*_x64_setup.exe, or Kitab_*_x64_portable.zip to run without installing |
| Windows on Arm | The x64 downloads, which Windows runs through its emulation |
| macOS, Apple silicon | Kitab_*_aarch64.dmg |
| macOS, Intel | Kitab_*_x86_64.dmg |
| Linux | .flatpak, .AppImage, .deb, .rpm or .tar.gz (x86_64; all but the Flatpak also for aarch64) |
Or install with a package manager:
# macOS, Homebrew
brew install --cask t21dev/tap/kitab
# Windows, Scoop
scoop bucket add t21dev https://github.com/t21dev/scoop-bucket
scoop install t21dev/kitabUnsigned builds. The downloads aren't code-signed yet. On Windows, SmartScreen may say "Windows protected your PC": choose More info, then Run anyway. On macOS, the first time, right-click Kitab in Applications and choose Open. Every release lists the SHA-256 checksum of each file.
Flatpak. Install the bundle with flatpak install --user Kitab_*_x86_64.flatpak; Flatpak fetches the Freedesktop runtime from Flathub. Kitab can read and save files in your home folder and on external drives, and has no network access: Flatpak brings the updates. To make it the default app for PDFs, use your system's Default Applications settings.
AppImage. chmod +x Kitab_*.AppImage and run it. The .deb, .rpm and .tar.gz also install a thumbnailer, so file managers show page 1 of your documents.
| Books, set in your typeface | Math in Markdown |
|---|---|
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| Mermaid diagrams | Command palette |
|---|---|
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Kitab is a native program. The window, the tabs and every page are drawn by GPUI, the GPU UI framework the Zed editor is built on, and the pages come from MuPDF, the engine behind SumatraPDF. Nothing in between is a web page.
The speed comes from a few rules the code is held to (AGENTS.md):
- Nothing extra before the first page. On Windows the first page is painted with plain GDI while the GPU window starts up behind it, so a double-clicked PDF shows its page straight away. Update checks, keymaps, thumbnails and the library wait until after.
- The UI thread never waits. Opening, rendering, searching and saving run on a pool of MuPDF workers. Several threads render one document's pages at once, and a quick soft render stands in while the sharp one draws.
- Only what you can see. Pages and thumbnails outside the view are skipped, and the page cache is capped in bytes, not pages, so memory stays bounded however long the document is.
- Measured against SumatraPDF.
kitab-benchtimes start-up, first page, scrolling and memory against SumatraPDF on the same machine, from the app's own window. The 0.1.0 numbers will be published with the release, measured, not estimated.
| Format | Notes |
|---|---|
| Password-protected files too. Links, contents, text selection, annotations already in the file | |
| EPUB | Flowing and fixed-layout, right-to-left books, every script your system has fonts for |
| MOBI, FB2, TXT | Flow like EPUB, in your typeface and text size |
| CBZ | Comics, page by page |
| XPS | Pages at their own size |
| Markdown | Tables, task lists, footnotes, code with syntax colours, math, Mermaid diagrams, frontmatter |
Kitab is a document reader, so it leaves image files to your image viewer.
Reading
- Each page keeps its own size and shape, so mixed portrait and landscape PDFs look right
- Fit width, fit page, actual size, Ctrl+wheel zoom and rotation
- Remembers the page, zoom and layout of every file, and reopens your tabs after a restart
- Find (Ctrl+F) with match case and whole word, hits highlighted on the page
- Contents, page thumbnails, bookmarks (Ctrl+D) and your marks, all in the sidebar
- Back and forward through where you've been, with Alt+Left and the mouse's side buttons
- Presentation mode (F5): one page at a time, full screen on black
- Minimal mode (F11) hides everything but the page
Books
- Pages re-flow to fill the window, and zoom changes the text size
- Typeface (the book's own, serif, sans or mono), line spacing and margins
- Right-to-left books turn the other way, and fixed-layout books keep their spreads
Markdown
- Reads like a document, not a code file, with an outline in the sidebar
- Math typeset natively, Mermaid diagrams drawn in your theme's colours
- Edit beside a live preview (Ctrl+E), and it reloads when another editor saves the file
Marks and notes
- Highlight, underline or strike through text, add notes and text boxes
- Pen, highlighter, lines, arrows, rectangles and ellipses, in any colour you can type as hex
- Ctrl+S saves marks into the PDF as standard annotations, which other readers show too
- Export your marks to Markdown or CSV
PDF tools, on your machine
- Save pages as a new PDF, merge PDFs, save a page as PDF, image or text
- Split view: two documents side by side
Keyboard and look
- SumatraPDF's shortcuts where it has one, a command palette (Ctrl+K), and a
keymap.jsonfor your own - Seven themes (Dark, Light, Paper, Ink, Nord, Noctua, Vampire), any accent colour, three densities
- A quick dock you can move to any edge, choose the buttons of, or tuck away
Windows
- One window: double-clicking another file opens it as a tab
- Page thumbnails in File Explorer, and Settings to make Kitab the default app per file type
Coming next: native printing, verifying and signing PDFs, more page tools, and library search. The roadmap has the order.
Your files stay on your computer, and there is no account, no analytics and no telemetry. Kitab connects to one service on its own: GitHub, shortly after start-up and every six hours, to ask for the latest version number. Settings › About turns that off. Links you click open in your browser. The details are in PRIVACY.md.
You need Rust stable (see rust-toolchain.toml) and libclang for the MuPDF bindings.
cargo run -p kitab -- tests\fixtures\pdf\01-text-outline.pdf
cargo test --workspace
cargo clippy --workspace --all-targets -- -D warnings
python tools/check_source.py # licence headers, no colour literals outside kitab-theme
cargo deny checkRelease packages: python tools/build_release.py, then python tools/package.py <version> (an installer, portable zip, dmg, or on Linux the .tar.gz, .deb, .rpm and .AppImage). The Flatpak builds offline from packaging/flatpak/dev.t21.kitab.yml; its header lists the steps.
The tests read a corpus of PDF, EPUB and Markdown fixtures with an expected.json oracle. To rebuild it:
python -m venv tests\fixtures\tools\.venv
tests\fixtures\tools\.venv\Scripts\pip install -r tests\fixtures\tools\requirements.txt
tests\fixtures\tools\.venv\Scripts\python tests\fixtures\tools\generate_fixtures.py --large
tests\fixtures\tools\.venv\Scripts\python tests\fixtures\tools\verify_fixtures.pycrates/
kitab the app: start-up, first frame, adapters
kitab-ui GPUI views: shell, tabs, reader, sidebar, settings
kitab-mupdf MuPDF on a pool of worker threads
kitab-md Markdown parsing, sanitising, highlighting, math
kitab-store the library database (SQLite), forward-only migrations
kitab-theme colour tokens and the themes
kitab-os Windows, macOS and Linux glue: data folder, file types, single instance
kitab-shell the File Explorer thumbnail provider
kitab-bench start-up and scroll benchmarks against SumatraPDF
docs/PLAN.md decisions, architecture, performance budgets, roadmap
DESIGN.md the design system: tokens, depth, type, components, motion
AGENTS.md rules for changing the code
Read AGENTS.md first. Commits follow Conventional Commits, every user-visible change adds a line to CHANGELOG.md, and a bug fix comes with a test that fails without it.
Kitab is free software under the GNU AGPL 3.0 or later.
Built on MuPDF by Artifex (AGPL), GPUI by Zed Industries, pulldown-cmark, syntect, mermaid-svg and resvg. The Nord theme's colours come from Nord. The full list is in NOTICE.
Kitab Reader is made by t21 dev and TriptoAfsin.