Compare AI models

Specifications
Context windowHow much text the model can hold in mind at once — your question, any documents you attach, the conversation so far, and its own reply. Go past it and the earliest part falls out of view.
—1.05M
API pricingUSD per 1M tokens · lower wins · base tier
Input priceWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it.
—$10.00
Output priceWhat you pay for the text the model writes back. It is normally the dearer half: producing an answer costs more than reading one.
—$50.00
Cached input priceA reduced rate for text you send over and over. If every request starts with the same instructions or the same document, the provider keeps a copy ready and charges less to read it again.
—$1.00
Cheapest inputLowest input rate across every provider on OpenRouter, the lab included. The cheapest endpoint may run a quantised build or a shorter context — see "Available from" on the model page.
—$5.00OpenAI
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
—$25.00OpenAI
—$4,500OpenAI list price
Benchmarks
BullshitBench v2Nonsense detection — Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better.
46%69%
GPQA DiamondScience — Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better.
59.4%96%
Overview
CompanyAnthropicOpenAI
Release dateJun 20 2024Sep 3 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

GPT-6 Astra leads Claude 3.5 Sonnet on 2 of the 2 benchmarks they both report (BullshitBench v2, GPQA Diamond). Only GPT-6 Astra has a verified first-party API price: $10.00 per million input tokens and $50.00 per million output tokens. No pay-as-you-go API rate is tracked for Claude 3.5 Sonnet. Claude 3.5 Sonnet shipped 805 days before GPT-6 Astra, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

On BullshitBench v2, GPT-6 Astra leads at 69% vs Claude 3.5 Sonnet at 46%. On GPQA Diamond, GPT-6 Astra leads at 96% vs Claude 3.5 Sonnet at 59.4%.