Why Rebuild the Wheel?

"Why build another LaTeX editor? Overleaf exists." This is the most common question I get about LetX.

The answer is simple: Latency.

Overleaf compiles your document on the server. You type, you wait 2-5 seconds, you see the PDF. In 2026, 5 seconds is an eternity.

Client-Side Rendering with WebAssembly

LetX doesn't wait for a server. We compiled the TexLive engine to WebAssembly (WASM). When you type \frac{a}{b}, it compiles in your browser in 50ms.

Zero network lag. You can write complex papers on a plane without internet.

Multiplayer with CRDTs (Yjs)

Collaboration in Overleaf often leads to "User A overwrote User B's changes" conflicts on bad connections.

We implemented Yjs, a Conflict-free Replicated Data Type (CRDT) library.

• It treats the document as a stream of detailed updates, not just text blocks.
• It guarantees eventual consistency mathematically.
• Offline support is native: you can edit offline for hours, come back online, and it merges perfectly.

The UI: Editor as a Canvas

We moved away from the "Text on Left, PDF on Right" split. LetX introduces "Block Mode". Equations render inline as you type, similar to Notion but with full LaTeX power. You only view the full PDF when you are ready to export.

Conclusion

LetX isn't just an "Overleaf Clone". It is a re-imagining of scientific writing for the modern web—offline-first, instant, and collaborative by default.

FAQ

Q: Does LetX work on iPad? A: Yes, since the compilation happens in JS/WASM, it runs on any modern browser, including iPadOS.

Q: Can I collaborate with Overleaf users? A: Not directly in real-time. You must export/import via ZIP.

Q: How big is the initial download? A: The WASM binary is ~35MB compressed. It caches after the first load, making subsequent loads instant.

Q: Is it open source? A: The UI components are, but the core engine is proprietary to Shahriar Labs.

Q: Do you support BibTeX? A: Yes, with Zotero integration coming in Q3.