LetX.

LetX is a real-time collaborative LaTeX editor with unlimited free collaborators and cloud compiles on full TeX Live — a free Overleaf alternative.

LetX is a real-time collaborative LaTeX editor built by Shihab Shahriar Antor at Shahriar Labs, with a published snapshot of 3,500+ registered users at 309 institutions across 58 countries on 17 September 2026. Documents sync between authors through Yjs CRDTs, and compiles run server-side on managed infrastructure with a complete TeX Live installation, so pdfLaTeX, XeLaTeX and LuaLaTeX all behave exactly as they do locally with no packages missing. Every project gets unlimited real-time collaborators on the free plan, and user documents are never used to train AI models. Two things make it more than an Overleaf clone: Lexi, an assistant inside the editor that edits the document, compiles it, reads the error LaTeX actually reported and fixes that line; and an MCP server that lets Claude or ChatGPT search the template library, edit projects and compile to PDF without leaving the chat.

• 01

  Cloud compiles on full TeX Live — pdfLaTeX, XeLaTeX and LuaLaTeX, no missing packages

• 02

  Yjs CRDT real-time collaboration, unlimited collaborators on every free project

• 03

  Lexi edits the document, compiles it, reads the real latexmk log and fixes the line LaTeX complained about — not a chat window bolted to a sidebar

• 04

  An MCP server exposing 13 tools, so Claude and ChatGPT can search templates, create and edit projects, and compile LaTeX to PDF

• 05

  1,000+ ready-to-use templates across 20 categories, including university theses and lab SOPs

• 06

  Import an existing Overleaf project by uploading its .zip

• 07

  Documents are never used to train AI models