Compare quality, speed, and cost across multiple AI providers with one prompt.
Try It Now
See how different AI models respond to the same prompt — no API keys needed.
Supported Providers
OpenAI
Anthropic
Google AI
DeepSeek
xAI (Grok)
Groq
Mistral AI
Perplexity
Together AI
Cerebras
Fireworks AI
Simple, Transparent Pricing
Free — $0
All supported AI providers
Choose any model versions
Compare 2 providers at once
Save up to 50 test histories
Your own API keys
Builder — $19/month
Everything in Free, plus:
5,000 API calls/month
Compare 3+ providers at once
Save 500 test histories
CSV & data export
Performance drift analytics
Overages at $0.005/call
Scale — $49/month
Everything in Builder, plus:
25,000 API calls/month
Save 2,000 test histories
Priority support
Overages at $0.003/call
Frequently Asked Questions
What is Promptster?
Promptster is a SaaS platform that lets you test and compare AI model responses side by side. Send the same prompt to multiple providers — OpenAI, Anthropic, Google, DeepSeek, xAI, Groq, Mistral, Perplexity, Together AI, Cerebras, and Fireworks AI — and compare response quality, speed, cost, and token usage in real time.
Do I need to provide my own API keys?
Yes. Promptster uses a BYOK (Bring Your Own Keys) model. You provide API keys from each provider you want to test. Your keys are encrypted with AES-256 and never leave your device in plaintext.
Which AI providers are supported?
Promptster supports multiple providers including OpenAI, Anthropic, Google AI, DeepSeek, xAI, Groq, Mistral, Perplexity, Together AI, Cerebras, and Fireworks AI.
How does cost tracking work?
Promptster calculates costs in real time using each provider's published per-token pricing.
Is there a Public API?
Yes. Promptster offers a Public API (v1) for programmatic access.
What are Scheduled Tests?
Scheduled Tests let you automatically run a prompt against a provider on a recurring schedule.
How are my API keys secured?
API keys are encrypted client-side using AES-GCM-256 before being stored.
What plans are available?
Free includes all supported providers, 2-way comparisons, 500 API calls/month, and 50 saved tests. Builder ($19/month) adds 5,000 calls/month, 3+ provider comparisons, 500 saved tests, CSV export, and data export. Scale ($49/month) adds 25,000 calls/month, 2,000 saved tests, and priority support.
Ready to find your perfect AI model?
Start comparing AI providers in seconds. No credit card required.