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
DeepSWE 1.1Agentic coding — Artificial Analysis' independent test of deep, agentic software-engineering work — the AI has to plan and carry out substantial coding tasks end to end. (Version 1.1 of the test.) Higher is better.
10%74.1%
ARC-AGI-2Abstract reasoning — Puzzle-style tests of abstract reasoning and pattern-finding — the kind of thing people find easy but AIs often struggle with. Higher is better.
42.5%95%
GPQA DiamondScience — Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better.
89.5%96%
Overview
CompanyMetaOpenAI
Release dateApr 8 2026Sep 3 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

GPT-6 Astra leads Muse Spark on 3 of the 3 benchmarks they both report (DeepSWE 1.1, ARC-AGI-2, 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 Muse Spark. Muse Spark shipped 148 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 DeepSWE 1.1, GPT-6 Astra leads at 74.1% vs Muse Spark at 10%. On ARC-AGI-2, GPT-6 Astra leads at 95% vs Muse Spark at 42.5%. On GPQA Diamond, GPT-6 Astra leads at 96% vs Muse Spark at 89.5%.