For teams shipping LLM features in production

Catch prompt regressions before they hit production

Run evals on every prompt change. Compare outputs + scores, and block bad releases when quality drops.

Diff outputs across versions + models
Pass/fail quality thresholds
Shareable PR report links

OpenAI • Anthropic • Google Gemini — BYOK • Keys encrypted • Not used for training

Customer Support Bot — Regression Test
Comparing:v12 (baseline)vsv13 (candidate)
FAIL

v12 Score

84%

v13 Score

71%

-13% regression

"How do I reset my password?"

v12:Clear steps with link
v13:Generic response, missing link

"I want to cancel my subscription"

v12:Empathetic + retention offer
v13:Abrupt cancellation link only
3 more failed examples...View full report

50

Test Cases

42

Passed

8

Failed

80%

Threshold: 85%

Features

Everything you need to ship prompts safely

A purpose-built toolkit for teams who need prompt QA they can trust.

Regression Suites

Build test datasets with expected outputs. Run them on every prompt change to catch regressions before they ship.

Quality Scoring

Set pass/fail thresholds for your evals. Block releases that don't meet your quality bar automatically.

Prompt & Output Diff

See exactly what changed between prompt versions. Visual diffs show where outputs broke and why.

Model Matrix

Test the same prompt across OpenAI, Anthropic, and Google side-by-side. Find the best model for your use case.

Shareable Reports

Generate links for PRs, Slack, or stakeholder reviews. Everyone can see test results without an account.

BYOK + Secure Storage

Bring your own API keys. They're encrypted at rest, never logged, and stay under your control.

Built for real LLM use cases

Catch regressions specific to your application

Support Bot

Prevent tone and accuracy regressions in customer-facing responses.

SQL / Tool Agent

Prevent unsafe queries and incorrect tool actions before they execute.

RAG Answers

Prevent citation gaps and coverage drops in retrieval-augmented responses.

How it works

From setup to quality gate in minutes

No complex configuration. No steep learning curve. Just reliable prompt QA.

1

Create a regression suite

Start a project and define your test scenarios. Group related prompts, models, and test cases together.

2

Add test cases

Build your eval set with FAQs, edge cases, and expected outputs. Import from JSON or create directly in the app.

3

Run on every prompt version

Test each prompt change against your full dataset. Compare outputs side-by-side across models.

4

Set a quality gate

Define pass/fail thresholds. Block releases that regress below your quality bar.

5

Share the report in PRs

Generate shareable links for code reviews. Stakeholders see results without needing an account.

Bring your own API keys (encrypted)
We don't train on your data
Share reports without accounts
Pricing

Simple, transparent pricing

Start free, upgrade when you need more.

Free

$0

Best for trying out PromptLens

  • 2 projects
  • 5 prompts
  • 10 datasets
  • All LLM providers
Start free
Recommended

Pro

$29/month

For devs shipping LLM features

  • 10 projects
  • Unlimited prompts
  • Unlimited datasets
  • Email support
Start free

Team Plan — Coming Soon

Shared workspaces, admin controls, and dedicated support for production teams.

Join the waitlist

Ready to ship prompts safely?

Start catching regressions today. Set up your first eval in minutes and never ship a broken prompt again.

No credit card required • Free plan available