Character AI vs ChatGPT API

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

Character AI — create custom characters & chat ChatGPT API — GPT-4, o1 and o3 integration
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Paid from $9.99 $9.99
Updated 2025-11-26 2025-11-26

Character AI — create custom characters & chat

The API creates a character with a defined personality, traits and backstory, and keeps it consistent across a conversation.

Games, companion apps and interactive fiction use it where a generic assistant would break immersion.

Open Character AI — create custom characters & chat →

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 →

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Updated 2025-11-26 by Bilgisam Ltd. About