Compare AI models

Specifications
ParametersThe learned values that shape how a model responds. B means billion and T means trillion. For mixture-of-experts models, the total count is larger than the number active for each token. Parameter count alone does not measure quality.
671B—
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.
128k1.05M
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.
$0.27SiliconFlow$5.00OpenAI
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
$1.00SiliconFlow$25.00OpenAI
$104SiliconFlow · fp8$4,500OpenAI list price
Benchmarks
GPQA DiamondScience — Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better.
80.7%96%
Overview
CompanyDeepSeekOpenAI
Release dateSep 22 2025Sep 3 2026
AccessOpen WeightClosed
Model detailsView modelView model

Frequently asked questions

GPT-6 Astra leads DeepSeek V3.1 Terminus on 1 of the 1 benchmark they both report (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 DeepSeek V3.1 Terminus. DeepSeek V3.1 Terminus shipped 346 days before GPT-6 Astra, so benchmark comparisons should account for the intervening progress.

Context windows are 128k (DeepSeek V3.1 Terminus) vs 1.05M (GPT-6 Astra). DeepSeek V3.1 Terminus is open weight, while GPT-6 Astra is closed.

On GPQA Diamond, GPT-6 Astra leads at 96% vs DeepSeek V3.1 Terminus at 80.7%.