Langtail

You write prompts or build assistants in Langtail, run them against tests, and read the logs to see where your LLM app breaks.

Langtail is a low-code platform for testing and debugging AI applications and large language models, made for developers and teams who want prompt engineering to be less guesswork.

The free plan has unlimited users, 2 prompts or assistants, 1,000 logs a month and 30 days of data retention.

That is enough to try it on one small project, but not much more.

Pro costs $99 a month plus VAT for 1 user, 20 prompts or assistants, unlimited logs and 90 days of retention.

Team is $499 a month plus VAT for

10 users, unlimited prompts or assistants, a year of retention, Radars and Alerts, and dedicated support.

Enterprise is custom priced and adds an AI Firewall and self hosting.

Every plan lets you share apps publicly.