Find the cheapest AI model that passes your quality bar. Compare quality, speed, and cost across all major providers — zero markup on tokens.
AI Cost Savings Calculator
See how much you could save by switching routine tasks to a cheaper model.
Supported Providers
OpenAI
Anthropic
Google AI
DeepSeek
xAI (Grok)
Groq
Mistral AI
Perplexity
Together AI
Cerebras
Fireworks AI
Simple, Transparent Pricing
Free — $0
2,000 API calls/month
All supported AI providers
50 saved test histories
5 req/min rate limit
Builder — $9/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 — $29/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.
Will I actually save money with Promptster?
Yes. Most users discover that 40-70% of their AI tasks can be handled by a cheaper model with comparable quality. A single optimized comparison that redirects even a fraction of your API spend to a cheaper provider pays for the subscription many times over.
Do I need to provide my own API keys?
Yes — and that's a feature, not a limitation. With BYOK, you pay providers directly at their published rates with zero markup from Promptster. There's no token surcharge, no hidden fees, and no vendor lock-in. 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?
Every test shows real-time cost calculated from each provider's published per-token pricing, broken down by input and output tokens. After a comparison, Promptster highlights cost-saving opportunities — showing exactly how much you'd save by switching, along with quality and speed trade-offs.
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, 2,000 API calls/month, and 50 saved tests. Builder ($9/month) adds 5,000 calls/month, 3+ provider comparisons, 500 saved tests, CSV export, and data export. Scale ($29/month) adds 25,000 calls/month, 2,000 saved tests, and priority support.
How much does a typical comparison cost in provider API tokens?
Most comparisons cost $0.001-$0.05 in provider fees. A short prompt across 3 mid-tier models typically costs under $0.01. Promptster shows exact cost per response in real time.
Start saving on AI costs today
One comparison is all it takes to find where you're overpaying. Free forever — no credit card required.