Test prompts across all major models
Most teams lack a reliable way to test LLM prompts before shipping, leading to broken outputs in production.
“We test prompts by asking ChatGPT if it looks good”
“Our QA process is someone scrolling through outputs”
“We broke production because someone changed a system prompt”
A purpose-built toolkit for teams who need prompt QA they can trust.
Build test datasets with expected outputs. Run them on every prompt change to catch regressions before they ship.
Set pass/fail thresholds for your evals. Block releases that don't meet your quality bar automatically.
See exactly what changed between prompt versions. Visual diffs show where outputs broke and why.
Test the same prompt across OpenAI, Anthropic, and Google side-by-side. Find the best model for your use case.
Generate links for PRs, Slack, or stakeholder reviews. Everyone can see test results without an account.
Paste your prompt, add test cases with expected outputs, and run evaluations to get pass/fail results in minutes.
Add your system prompt and configure the model.
Define inputs and expected outputs.
Get pass/fail results, share with your team.
PromptLens replaces manual prompt checking with automated regression testing. Just paste your prompt, add test cases, and share results.
You'll stop eyeballing outputs and start actually testing them.
You'll catch regressions before they hit production.
You'll share results in PRs instead of Slack back-and-forth.
Start free with 3 projects and 50 evaluations per month. Upgrade to Pro at $99/month for unlimited projects, evaluations, and team access.
Best for trying out PromptLens
For teams shipping LLM features
| Feature | Free | Pro |
|---|---|---|
| Projects | 3 | Unlimited |
| Evaluations | 50/month | Unlimited |
| Share links | 3 | Unlimited |
| Team members | — | 10 |
| Version comparison | — | |
| Price | $0 | $99/month |
Common questions about setup, model support, pricing, and how PromptLens fits into your existing workflow.
Unit tests check if code runs correctly. PromptLens checks if LLM outputs are actually good. You define expected behaviors, and we evaluate whether prompt changes maintain or improve output quality across your entire test suite.
Most teams run their first evaluation within 5 minutes. Create a project, add a few test cases, and run your prompt against them. No complex configuration or infrastructure required.
GPT-5, Claude, Gemini, Llama, DeepSeek, Mistral, and more. Run the same test cases across 25+ models to find what works best for your use case.
Yes. Run the same prompt and test cases across different models side-by-side. Compare GPT-4 vs Claude vs Gemini to find the best model for your specific use case.
No. PromptLens fits into your existing process. Generate shareable report links for PRs, Slack, or stakeholder reviews. No one needs an account to view results.