Loading tool…
Spreadsheet-style workbench for writing, testing and shipping prompts, with a firewall on the outputs
Langtail treats a prompt as something that has to be tested before it ships. Prompts live in a spreadsheet-like table that non-developers can edit, test suites run them against saved cases, and the same prompt can be replayed across models and parameter settings so the results can be compared side by side. A separate firewall layer screens for prompt injection and unsafe output at runtime. There is a typed TypeScript SDK and an OpenAPI spec, connectors for OpenAI, Anthropic, Google, Meta and Mistral, and a self-hosted option for teams that cannot send prompts out. The vendor is LANGTAIL.COM s.r.o., registered in Prague. The address this product was harvested under now redirects here.
Free tier at zero, Pro at 99 dollars a month and Team at 499, all quoted plus VAT; Enterprise is negotiated. The home page shows no figures at all — they are only on the plan page.
Use tool ↗The useful idea is treating prompts like code that needs a test suite, and then handing the editing surface to people who do not write code. Cross-model replay makes swapping providers a measurable decision rather than a leap, and the firewall covers a risk most prompt tools ignore entirely. The step from free to 99 dollars a month is abrupt for a solo developer, and a Czech company of this size is a smaller bet than the observability platforms it competes with.
Watch out: The harvested address for this product is an old domain that now redirects; bookmark the current one so links do not break later.
Side-by-side fact sheets against the competitors our research names — pricing, platforms, API and both verdicts on one page.
No reviews yet — be the first to review Langtail.
Reviews are tied to your EffectHub account — one review per tool, so the rating for Langtail reflects real users.
No questions yet — ask the first one about Langtail.
Questions about Langtail are tied to your EffectHub account, so answers can reach you and the section stays free of spam.