Compare AI models

Specifications
Context windowHow much information the model can work with in one request, measured in tokens — pieces of words or other data. This includes your question, attachments, conversation and reply. Limits can vary by model variant and provider.
1M1.05M
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.
$0.10$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.
$0.50$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.
$0.004$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
$45.00Meta list price$4,500OpenAI list price
Benchmarks
AA Coding Agent IndexAgentic coding — Artificial Analysis' overall score for coding agents, combining three coding benchmarks with what each run costs and how many tokens it burns. It rates a model paired with a particular agent harness rather than the model alone, so the same model scores differently in different tools. Higher is better.
4667
Terminal-Bench 4.0Agentic terminal coding — Can the AI work in a command-line terminal — running commands and finishing technical setup tasks the way a developer would? Version 4.0 recalibrated how much time, CPU and memory each task gets, removed eight tasks and fixed nineteen, so fewer runs fail for reasons that have nothing to do with the model. Scores are not comparable with earlier versions. Higher is better.
40.9%57.9%
Overview
CompanyMetaOpenAI
Release dateNov 9 2026Sep 3 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

GPT-6 Astra leads Muse Ember on 2 of the 2 benchmarks they both report (AA Coding Agent Index, Terminal-Bench 4.0). Muse Ember is cheaper on both input and output: $0.10 vs $10.00 per million input tokens, and $0.50 vs $50.00 per million output tokens. Figures are base-tier rates. GPT-6 Astra shipped 67 days before Muse Ember, so benchmark comparisons should account for the intervening progress.

Context windows are 1M (Muse Ember) vs 1.05M (GPT-6 Astra).

On AA Coding Agent Index, GPT-6 Astra leads at 67 vs Muse Ember at 46. On Terminal-Bench 4.0, GPT-6 Astra leads at 57.9% vs Muse Ember at 40.9%.