NewPDF editor, file converter & Locker

One workspace to write, draw, and ship.

A rich text editor with AI, an infinite whiteboard, and PDF, compression and conversion tools that run in your browser — plus a private Locker for the files you share once.

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Free forever · No card · Nothing uploaded by file tools

<50ms
Keystroke latency
8
Tools, one shell
0
Files uploaded to compress
1×
Locker links open once

Built on open source you already trust

Next.jsTipTapExcalidrawpdf.jsTailwind CSSTypeScriptRadix UIMongoDBAuth.js
Capabilities

A productivity stack, reimagined.

Writing, drawing, PDFs and private files under one roof — and one shortcut.

Rich text editor

Notion-grade writing surface: slash menu, block drag handles, tables, code blocks, pagination and export to PDF or DOCX.

Infinite whiteboard

Excalidraw canvas for diagrams and wireframes — or describe one and let AI draw it.

Edit PDF text

Click any line and retype it in place. Fonts, images and annotations stay untouched.

Merge & organise PDFs

Combine files, then reorder, rotate, duplicate or drop pages before you export.

Convert anything

Images ↔ PDF, DOCX, WebP, AVIF, SVG; PDF and DOCX to Word, EPUB, Markdown or HTML.

Locker

IDs, records and contracts encrypted at rest. Share with a link or QR that opens once, then dies.

Smart compression

Images and PDFs shrink in-browser via WebAssembly. Nothing is uploaded, so nothing can leak.

AI co-writer

Inline rewrites, summaries and translation from the same slash menu.

Share by link or QR

Publish a read-only view of any document and hand it over with a scan.

Keyboard-first, always

Every action is mapped. The mouse is optional.

⌘K⌘/⌘⇧D⌘E⌘↵
Why Lumen

Built for people who ship.

Every decision is optimized for speed, privacy, and focus — not engagement metrics.

  1. 01

    Latency is a feature

    Sub-frame keystroke response on any device. The editor never gets in the way.

    <50ms
  2. 02

    File tools never upload

    Compression, conversion and PDF editing run entirely in-browser through WebAssembly.

    0 uploads
  3. 03

    Sensitive files are shared once

    Locker links open a single time, expire on a timer, and can be revoked until they are opened.

    1 view
  4. 04

    One shell, eight tools

    Editor, whiteboard, PDF editor, merger, compressor, converter, Locker and documents share one nav and one shortcut set.

    8 tools
  5. 05

    Keyboard over chrome

    Every action is mapped. Slash menu, drag handles, and inline commands throughout.

    80+ shortcuts
  6. 06

    Open formats, no lock-in

    Export to PDF, DOCX, Markdown or HTML at any time. Your work is never trapped in a proprietary blob.

    4 exports
FAQ

Questions, answered.

Still stuck? Reach us at hello@lumen.app and a human replies.

Is Lumen really free?

Yes. The Free plan is forever free with unlimited documents, whiteboards, Locker storage and every file tool. Paid plans add collaboration and higher AI limits when they launch.

Can I edit an existing PDF?

Yes. Open it in Edit PDF, click any line of text and retype it in place, add new text, shapes or whiteout, and rotate or remove pages. Only what you changed is rewritten, so fonts, images, links and annotations come back untouched.

Are my files uploaded when I compress or convert them?

No. Compression, conversion, PDF merging and PDF editing all run in your browser via WebAssembly. There is no upload endpoint behind those pages — you can watch the network tab and confirm it.

What is the Locker?

A private space for IDs, records and contracts. Files are encrypted at rest, and each share link or QR code opens exactly once before it dies. You can set an expiry and revoke any link that has not been opened yet.

Which formats can I convert between?

Images to PDF, DOCX, JPG, PNG, WebP, AVIF, GIF, BMP, TIFF, ICO or SVG. PDF and DOCX to Word, ODT, RTF, EPUB, Markdown, HTML, plain text or page images. Several files can be merged into one PDF.

How does the AI co-writer work?

Select text and ask for a rewrite, summary or translation from the slash menu or bubble menu. On the whiteboard, describe a diagram and it is laid out for you. Requests are rate-limited per account.

Can I share a document with someone who has no account?

Yes. Publish a read-only share link or QR code for any document or whiteboard. Viewers need nothing but the link; you can unpublish at any time.

Does it work offline?

Lumen is an installable PWA. Documents you have opened keep working without a connection and sync when you are back online.

Get started

Ship better, faster.

Create a free account and your docs, boards, PDFs and Locker follow you everywhere.

Open the editorSee what's inside