LLM APIs · S-tier
OpenAI API
Usage-based API for GPT models, images, and audio. The default when a product needs a frontier model.
Best for
Products that want the broadest model, tool, and SDK support.
What it is
The OpenAI API is the usage-based platform for GPT models plus image and audio endpoints. It is the default integration when a product needs a widely supported frontier model and the usual SDK examples. New accounts sometimes get credits; ongoing use is paid.
Score breakdown
Pricing
Paid
Starting price: check site
Usage-based. Introductory credits come and go. Budget from the pricing page, not from memory.
Dates
Released Jun 2020 (month precision).
Added to StackPick 14 Oct 2026.
Alternatives
A-tier · 88
Anthropic API
Production apps that want Claude specifically, especially for long documents and code.
A-tier · 88
Gemini API
Apps that want Gemini, multimodal inputs, and a real free tier to prototype.
A-tier · 87
OpenRouter
Switching models without rewriting the client, or failing over when one lab is down.
Comparisons
Questions
What is OpenAI API best for?
Products that want the broadest model, tool, and SDK support.
How much does OpenAI API cost?
Paid. Starting price: check site. Usage-based. Introductory credits come and go. Budget from the pricing page, not from memory.
What are alternatives to OpenAI API?
Anthropic API, Gemini API, OpenRouter are the alternatives we file next to it. Open a comparison when one exists.