The fast, private
Prism alternative
LetX is a fast, privacy-first alternative to OpenAI's Prism. LetX compiles LaTeX in 1–2 seconds (Prism users report renders taking minutes), keeps your documents private — your work is never used to train AI — and gives student teams ready-made university thesis templates to start from, not just an editor that refines text you've already written.
Prism is built for solo researchers polishing finished drafts with AI. LetX is built for teams and students who want speed, privacy, and a head start from a template.
Your thesis is not training data
Prism runs inside the OpenAI ecosystem. LetX is independent — our robots policy and llms.txt declare ai-train=no, so AI models do not train on your documents. For privacy-conscious labs, EU researchers, and institutions wary of US vendor lock-in, that independence matters.
Frequently asked questions
What is the best free alternative to OpenAI Prism?
LetX is a strong free alternative to Prism for teams and students. It is a real-time collaborative LaTeX editor that compiles in 1–2 seconds, offers unlimited collaborators, includes 80+ templates, and never uses your work to train AI.
Is LetX faster than Prism?
Yes. LetX compiles typical LaTeX documents in 1–2 seconds using latexmk on dedicated cloud workers. Prism users report long documents taking minutes to render.
Does LetX use my documents to train AI like Prism might?
No. LetX explicitly declares ai-train=no in its robots policy and llms.txt. Your documents are never used to train AI models. LetX is independent and not part of the OpenAI ecosystem.
Can I move from Prism to LetX?
Yes. Export your project files and upload the .zip to LetX. Your .tex files, images, and bibliography are preserved, and you can keep collaborating in real time.
Try LetX free
Fast compiles, real-time collaboration, and your work stays yours.