Slab

Free, open-source PDF tools for macOS, Windows, and Linux.

Read, merge, split, convert, sign, and redact PDFs. Core tools run locally; optional AI uses your configured provider.

Download Slab · Website · Report an issue · Changelog · Server docs · Plugins

A quick first run: open a PDF, press ⌘K, and choose Merge, Sign, or Redact. The feature tour below previews the workflow.

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Features

Feature	What you can do
Merge & split	Combine PDFs, split by page ranges or chapters, or divide into balanced files.
Arrange pages	Reorder, rotate, delete, duplicate, or insert blank pages, with undo and redo.
Convert	Convert PDF content to Word, Excel, Markdown, or HTML; create PDFs from other formats.
OCR & extraction	Make scans searchable and extract text, images, or tables to CSV.
Edit & format	Edit text, crop pages, add watermarks, headers, footers, page labels, and Bates numbers.
Sign & redact	Place signatures, remove sensitive content, and sanitize hidden data.
Compare	Inspect text and visual differences between document versions.
Forms	Create, fill, and flatten interactive PDF forms.
Automate	Process watched folders with reusable recipes and batch workflows.
AI assistance	Ask questions, find citations, create summaries, flashcards, and glossaries.
Create & present	Turn Markdown into PDFs and present PDFs as slides or in a focused reader.
CLI & server	Script PDF tasks from the command line or run a self-hosted HTTP API.
Appearance	Choose Light, Dark, OLED, White, or Glass, with nine accent colors.

OCR requires Poppler and Tesseract. AI uses your configured local or cloud provider.

Why Slab

🔒 Local-first	Core PDF tools run on your device. AI can also run locally with Ollama; cloud processing depends on the provider you configure.
⚡ Fast	Native Rust core. A hundred-file merge finishes before your coffee does.
🪶 Tiny	~15–25 MB installers. No Electron bloat.
💸 Honest	Free forever, GPL-3.0. No accounts, no telemetry, no "Pro" tier.

Take the tour

Beacon — AI with your choice of provider. Chat with citations, semantic search across your library, one-click PII redaction, summaries, study flashcards, glossary, and voice. Use Ollama for on-device AI, or configure an OpenAI-compatible endpoint.

The everyday craft. Merge a hundred files in a second. Drop a signature or an APPROVED stamp on any page. Burn redactions into the content stream. OCR a scanned stack into searchable text.

Find anything, instantly. A browsable library across every PDF you've imported, line-level diff between any two documents, and one ⌘K palette to reach all 65 tools.

OLED theme — true black

A fifth appearance option for emissive displays: true-black #000000 surfaces, so pixels switch off instead of glowing dark grey. Pick it in Settings, or press ⌘K and type "theme".

Glass theme — make it yours

Translucent panels over a softly tinted background, with nine accent colors: Orange, Cobalt, Iris, Emerald, Coral, Teal, Amber, Lime, and Slate. Choose Glass and your accent in Settings.

These screenshots show the current main branch. The Glass theme and PDF workflow polish will ship in the next release.

More PDF workflow screenshots — Split previews and Merge results

The compact panels keep page ranges, output filenames, and saved-file actions easy to reach.

Split — preview every output	Merge — arrange and save

Hopper — folders that file themselves

Point Hopper at a folder — ~/Downloads, a scanner, a shared inbox — and attach a recipe. New PDFs get flattened, OCR'd, redacted, watermarked, renamed by Beacon, and filed away, with a live log streaming every run.

Six predicate kinds route each file (filename, regex, text contents, page count, size, catch-all), and a live preview pane shows what each rule would catch against your actual recent files. ⇧⌘H to open it.

Hazel charges $42 and can't read PDFs. Adobe's automation needs an enterprise license and phones home. Hopper is free and local.

Slab Server — the same engine, in 80 megabytes

Headless Slab: an HTTP API plus a drag-and-drop web UI in a single Docker image. Put it on your NAS, script it, hide it behind a reverse proxy.

docker run --rm -p 8080:8080 ghcr.io/sanjays2402/slab:latest

Open http://localhost:8080, drop a PDF on the page.

The server is open by default. To require a key on every API call, set SLAB_API_KEY and send it as Authorization: Bearer <key> or X-Api-Key: <key>; use SLAB_BIND=127.0.0.1:8080 to listen on localhost only.

docker run --rm -p 8080:8080 -e SLAB_API_KEY=change-me ghcr.io/sanjays2402/slab:latest

Full API, configuration and Compose example: docs/server.md.

65 tools, one palette

See every tool — press ⌘K anywhere in the app to jump to any of them

Group	Tools
Read & organize	Reader · Library · Search Library · Pages · Pages (list) · Slides · Theater
Assemble	Merge · Split (balanced N files, live preview, overlap validation) · Split by Chapter · Insert · N-up · Flatten · Bind (PDF → EPUB)
Convert	PDF → Images · Convert · Reflow (PDF → Word) · Tabulate (PDF → Excel) · Markdown (PDF → MD/HTML) · Markdown → PDF · Compress · Compact · Streamline (Fast Web View) · Archive (PDF/A) · Press (PDF/X-4) · Grayscale
Edit	Remove Blank Pages · Edit Text · Crop · Watermark · Header/Footer · Page Labels · Numbers · Bates · Legal Stamp · Metadata
Protect	Encrypt · Redact · Auto-Redact · Veil · Sanitize · Sign · Signet · Batch Sign
Analyze	OCR · Extract · Tables → CSV · Diff · Compare · Compare 3-way · Repair
Beacon AI	Beacon AI · Beacon Search · PII Redact · Citations · Study · Glossary · Voice
Automate	Hopper (Watched Folders) · Atelier (Recipes) · Quill Batch · Quill Designer · Quill Auto-Detect
Create	Forms · Toolbox · Loom (PDF/UA) · Loupe (PDF/A check)

Also in the box

• Standalone CLI — a separate slab binary ships in every bundle: slab autoredact in.pdf out.pdf --preset email,ssn, no GUI needed.
• Polyglot — point Slab at .docx .xlsx .pptx .epub .csv .json .html .rtf .odt, images (EXIF + OCR text), even audio (EXIF + transcription) and get PDFs out.
• Detachable panels — pop any panel into its own window. Beacon on the second monitor, two Readers side by side.
• Vim mode — modal keybindings (gg/G/j/k, counts, / search, :42) in Reader, Library, and Beacon.
• A11y & i18n — built-in accessibility audit, full keyboard control, and a JSON locale system.

Install

Pre-built installers ship with every release:

Platform	Files
macOS (Apple Silicon + Intel)	.dmg
Windows	.msi + .exe
Linux	.deb + .AppImage + .rpm

First launch on macOS: the builds are ad-hoc signed (no $99/year Apple Developer ID yet), so Gatekeeper warns once. Right-click Slab.app → Open → Open in the dialog. Every launch after is a normal double-click. Verify the signature yourself with codesign -dvv /Applications/Slab.app. To help fund a Developer ID so this prompt goes away for everyone, see SIGNING.md.

Build from source

Prereqs: Rust stable, Node ≥ 22.12, pnpm ≥ 9, plus the Tauri system dependencies for your platform (WebView2 and the MSVC build tools on Windows; webkit2gtk and friends on Linux).

git clone https://github.com/Sanjays2402/slab
cd slab
pnpm install
pnpm tauri dev          # run in dev mode
pnpm tauri build        # installer / app bundle for your platform

Optional runtime deps for the AI side: Ollama + ollama pull llama3.2:3b for Beacon chat; whisper-cpp for voice dictation. The settings panel tells you exactly what's missing.

Tests

pnpm check
pnpm test               # TypeScript, split planning, browser PDF helpers, i18n
pnpm exec playwright install chromium
pnpm test:e2e           # navigation and PDF workflows in Chromium
pnpm test:website       # published website, mobile, policies and screenshots
cargo test --locked --lib --bins --features server --manifest-path src-tauri/Cargo.toml
cargo build --locked --features server --bin slab --bin slab-server --manifest-path src-tauri/Cargo.toml
pnpm test:native        # actual CLI and HTTP API PDF round-trips

test:e2e starts Vite automatically. Native tests generate their own PDFs, use a temporary output folder and start the server on a local ephemeral port. Set SLAB_CLI / SLAB_SERVER for binaries in another location, SLAB_SITE_URL for another website deployment, or SLAB_CHROMIUM_PATH for an installed Chromium executable. Native dialog interactions in browser tests use a test bridge; test:native exercises the real Rust commands and HTTP server. OCR integrations need Poppler and Tesseract; AI integrations need configured providers.

Extend Slab

• Plugins and themes — write your own with the plugin guide and the slab-plugin-sdk; working samples live in examples/plugins.
• Marketplace — how listings are structured and submitted: docs/MARKETPLACE.md.

Contributing

Bug reports and pull requests are welcome. Before opening a PR, run pnpm check and pnpm test (see Tests); Rust changes should also pass cargo fmt and cargo clippy. Report security issues privately as described in SECURITY.md.

Under the hood

flowchart LR
    You --> UI["Slab UI\nSvelte 5 + TypeScript"]
    UI --> Core["Rust core\nlopdf"]
    Core --> Disk[("Your disk")]
    UI <-.-> Beacon["Beacon AI\non-device model"]
    Beacon <-.-> Disk
    Core <-.-> Server["Slab Server\nDocker, 80 MB"]

Loading

Tauri 2 shell, Svelte 5 front-end, pure-Rust PDF core (lopdf), pdfjs-dist rendering, Tesseract OCR, local embeddings + on-device chat for Beacon. 730+ Rust tests, clippy-clean, cross-platform CI.

A small promise

Slab will never ask for an email. Will never call home on its own (the optional update check only runs when you click it or opt in, and sends nothing about you). Will never gate a feature behind a paywall. If it ever does any of those things, you have my permission to fork it and rip the offending lines out.

Made with 🍰 by @Sanjays2402.

Terms & Disclaimer

By using this project you agree to the following.

• No warranty. This software is provided "as is", without warranty of any kind, express or implied, including merchantability, fitness for a particular purpose, and non-infringement.
• No liability. To the maximum extent permitted by law, the author and contributors are not liable for any claim, loss, or damage (direct, indirect, incidental, or consequential, including lost data or profits) arising from its use.
• Your responsibility. You use it at your own risk and are responsible for complying with the laws that apply to you.
• Redaction, signature, and standards-check (PDF/A, PDF/X, PDF/UA) results are not guaranteed and are not legal or compliance advice; always check the output.
• Third parties. Names, logos, APIs, and services of others belong to their owners and are used for identification only; no affiliation or endorsement is implied.
• Your statutory rights. Nothing here limits rights that cannot be waived by agreement, including under consumer-protection laws in the USA, Canada (including Quebec), and India (Consumer Protection Act, 2019).
• License. Use, copying, and distribution are governed by the LICENSE file; if anything here conflicts with it, the license controls.

Content, Assets & Fair Use

• Original work. Unless noted otherwise (including below), the code, text, design, and images in this repository were created by the author.
• Libraries, fonts, and icons. Third-party libraries, fonts (for example Google Fonts), and icon sets belong to their creators and are used under their own licenses; see the dependency manifests and each source for terms.
• Logos, brands, and screenshots. Third-party names, logos, and screenshots appear only to identify or describe their products (nominative use). They remain the property of their owners and do not imply affiliation or endorsement.
• Ideas and inspiration. Where this project is inspired by another product, game, or idea, it is an independent implementation. It borrows only general ideas, mechanics, or styles, which are not anyone's exclusive property, and is meant to contain no third-party code or artwork used without permission.
• Fair use and fair dealing. Any third-party material is used in limited ways for purposes such as education, research, review, commentary, or identification, relying on fair use in the USA (17 U.S.C. § 107), fair dealing in Canada (Copyright Act, ss. 29–29.2), and fair dealing in India (Copyright Act, 1957, s. 52), where they apply.
• Concerns and takedown requests. If you own rights in something here and believe it is used improperly, open an issue or contact the author through their GitHub profile with a link to the material and your claim. It will be reviewed promptly and credited, changed, or removed as appropriate. You may also use GitHub's DMCA process.
• Contributions. By contributing, you confirm you have the right to submit your contribution and agree it is licensed under this repository's license.
• Website. The project site has its own Terms and Fair Use pages.