One prompt. Every model.
The multi-model prompt testing tool built for developers who care about output quality. Run any prompt across 10 models simultaneously — watch responses stream in live, compare word-level diffs, score what works, and save the runs that matter.
Providers
6
Models
10
Execution
Parallel
Streaming
Live
No credit card required · Bring your own API keys
What makes Prism different
Features you won't find anywhere else
Per-model parameters
Set a different temperature, top_p, and max_tokens for each model in the same run. Compare Claude at 0.2 vs GPT-4o at 1.0 — simultaneously.
Live streaming + TTFT
Every response streams token by token. The “Fastest” badge goes to the first model to produce a token — not the first to finish. That's a different signal.
Injection testing
Built-in prompt injection and jailbreak test presets. Fire them at every model at once and see which ones hold — and which ones fold.
Templates remember everything
Save a named template and it restores your system prompt, user message, and exactly which models you had selected. Most tools save only the prompt.
Full capabilities
Everything you need to find the best model for the job
Multi-model execution
6 providers. 10 models. One prompt.
Claude, GPT-5.4, Gemini, Mistral, Groq, and xAI Grok run in parallel. Responses stream in as tokens arrive — no waiting for the slowest model to finish.
Latency visualization
VU meter. Per model.
Per-model latency bars show relative speed at a glance. Cost estimates appear on completion.
Diff view
Word-level diffs
LCS-based word diff between any two responses. Pick which two to compare when running 3+ models.
The model returnedgenerated a response.
It cited three sources with high confidence.
Run history
Save, name, tag, search.
Every run you save goes to your history with an optional name and free-form tags. Search across name, message, and tags. Restore any past run — prompt and model selection — directly into the playground with one click.
Personas
Preset system prompts
24 preset system prompts across 5 categories. Preview and edit each persona section by section before applying — or load one directly and keep editing in the field.
Export
Export as code
Any run exports to SDK code snippets. Copy the exact call that produced the response you want.
Key storage
AES-256 encrypted
Your API keys are AES-256-GCM encrypted before storage. Only the last 4 chars are ever returned to the client. Your full key is cryptographically inaccessible to us.
Scoring
Score every response
Rate each model's response 1–5 before saving. Your scores persist with the run in history.
How it works
Prompt to answer in three steps
Write your prompt
Enter a system prompt and user message. Load a persona preset, or pull from saved templates — prompt, message, and model selection restored in one click.
Pick models and parameters
Select any combination of Claude, GPT, Gemini, and more. Set a different temperature and max_tokens for each model if you want to make it a fair fight — or an unfair one.
Watch responses stream in
Every model streams live as tokens arrive. Score, diff, copy, or export any response. Save the run with a name and tags when you find something worth keeping.
Supported providers
Try the demo — no account required
3 free runs against Claude models. No API key. No signup. Just go.
Find your best model. Fast.
Bring your own API keys. Your keys, your data, your history. Start free — no credit card, no commitment.