Every frontier model, one key. No per-provider signup.
A prompt that works on Claude Opus 4.7 can tank on GPT-5.4. You find out by accident, after shipping. The tools you have turn every comparison into three browser tabs and a screenshot thread.
PromptLens is the comparison tool for developers picking models and sharing the answer.
Run the same prompt against every model you care about, outputs aligned row by row, scores on the right. No browser tab juggling.
OpenAI, Anthropic, Google, Meta, DeepSeek, Mistral. GPT-5.4, Claude Opus 4.7, Gemini 3 Pro on day one. One key. No per-provider signup.
Every comparison gets a shareable link. Send it to your team, a stakeholder, or an investor. No account required to view, no per-seat pricing.
Built-in metrics for similarity, keyword match, length range, regex, plus custom LLM-as-judge. Surfaces the winner without you eyeballing.
Pin a baseline run, then every new run lines up against it. You see which outputs moved, which scores dropped, and which model drifted first.
Attach a JSON schema to any prompt. We validate every model's response and fail the cell if it doesn't conform. Great for agent tool-call comparison.
90 seconds from blank page to a link your team can open.
Or pick a starter. Add a JSON schema if you want structured output validation.
One-click presets like GPT-5.4 vs Claude Opus 4.7 vs Gemini 3 Pro, or pick N models.
Every run produces a public URL. Paste in Slack, a PR, or a deck. No login needed to view.
Heavier platforms sell you workspaces, RBAC, and tracing you don't need yet. PromptLens owns one job: give you the best answer to "which model should I use for this prompt" in one link.
You'll stop opening three tabs to compare a prompt.
You'll pick the model by looking at the numbers, not by vibes.
You'll send one link instead of six screenshots.
Start free. Upgrade when you outgrow it. No seats, no surprise overage.
Common questions about PromptLens and how it compares to the tools you're already using.
No credit card. Shareable link in 90 seconds.