Building with AI? Then you know this pain.

Prompt A + Model B = Output C...
Until it suddenly doesn't.

Same input.
Same config.
Totally different output.

Because LLMs aren’t deterministic and when your product depends on stable responses, it feels like building on sand.

I got tired of playing prompt roulette.

Tired of:

• Copy-pasting prompts into playgrounds

• Switching models manually

• Changing temperature settings

• Scoring responses by eye

• Losing track of what worked and what didn’t

So I built PromptPerf

A fast, focused prompt testing playground built for serious AI builders.

🔍 Run your prompt across GPT-4o, GPT-4, GPT-3.5
🌡️ Test across temperatures
🔁 Check consistency over multiple runs
📊 Compare model outputs to your “ideal” result

No more guessing.
No more hope-it-works.
Just real validation.

Because vague outputs break trust.
And in AI — trust is your product.

PromptPerf is free to use.
Unlimited runs. 3 test cases per run.
More models and batch support coming.

Try it here → https://promptperf.dev

Would love your thoughts. 🙏