
GPT-6 Astra vs Gemini 3.8 Flash vs Claude Fable 5.1: Which AI Model Should You Choose in 2026?
An evidence-based comparison of GPT-6 Astra, Gemini 3.8 Flash, and Claude Fable 5.1 for reasoning, coding, research, agents, and API cost.
Choose a model and enter the expected usage. The calculator will show the total cost and the cost per request.
Input: $1 / 1M tokens · Output: $5 / 1M tokens
Input tokens are the text you send to the model. Output tokens are its response.
Estimated cost
$35.00
The calculator multiplies the tokens in one request by the number of requests, then applies the model rate per 1 million tokens. Input and output are calculated separately.
With reasoning models, some billable tokens may not appear in the response because the model uses them for internal computation. Leave some room for them in your estimate.
The estimate uses standard API rates. Caching and batch discounts, regional pricing, and paid tools are not included.
For 1,000 requests with 1,000 input and 500 output tokens, Anthropic — Claude Haiku 4.5 costs approximately $3.50.
Prices checked:
This is an early estimate. Check the provider’s website before launch because prices can change.
A real project also includes servers, data storage, monitoring, and development. I can help put together a more complete estimate.

An evidence-based comparison of GPT-6 Astra, Gemini 3.8 Flash, and Claude Fable 5.1 for reasoning, coding, research, agents, and API cost.