ChatGPT API vs GPT-5 API

Two Artificial intelligence APIs with a free plan, compared field by field.

ChatGPT API — GPT-4, o1 and o3 integration GPT-5 API — content generation & business automation
Endpoints 1 1
Latency
Service level
Free tier $0.00 $0.00
Paid from $9.99 $9.99
Updated 2025-11-26 2025-11-26

ChatGPT API — GPT-4, o1 and o3 integration

One endpoint onto the OpenAI model family, including GPT-4 and the reasoning models, for chatbots, support automation and workflow tools.

It removes the SDK and key-management step for products that only need the call.

Open ChatGPT API — GPT-4, o1 and o3 integration →

GPT-5 API — content generation & business automation

A REST front end to GPT-5 and other advanced models for text generation, business automation, content creation, chatbots, SEO writing and document analysis.

Setup is a single endpoint with secure integration and support for over 100 languages, which makes it usable without an SDK.

Open GPT-5 API — content generation & business automation →

Other comparisons in Artificial intelligence

Best free Artificial intelligence APIs →

Updated 2025-11-26 by Bilgisam Ltd. About