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. | 200k | 2M |
| API pricingUSD per 1M tokens · lower wins | ||
Input priceWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it. | $2.00 | — |
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. | $8.00 | — |
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. | $0.50 | — |
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. | $2.00OpenAI | — |
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input. | $8.00OpenAI | — |
| $800OpenAI list price | — | |
| These models have no shared benchmark scores. | ||
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. | 26% | — |
| Overview | ||
| Company | OpenAI | SpaceXSI |
| Release date | Apr 16 2025 | Sep 19 2025 |
| Access | Closed | Closed |
| Model details | View model | View model |
Other comparisons
o3vsClaude Haiku 5.5Grok 4 FastvsClaude Haiku 5.5o3vsGemini 4 ArgonGrok 4 FastvsGemini 4 Argono3vsMuse Spark OpenGrok 4 FastvsMuse Spark Openo3vsDeepSeek-V4.1-Flash-1017Grok 4 FastvsDeepSeek-V4.1-Flash-1017o3vsMistral Large 4Grok 4 FastvsMistral Large 4o3vsKimi K3Grok 4 FastvsKimi K3Frequently asked questions
o3 and Grok 4 Fast don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Only o3 has a verified first-party API price: $2.00 per million input tokens and $8.00 per million output tokens. No pay-as-you-go API rate is tracked for Grok 4 Fast. o3 shipped 156 days before Grok 4 Fast, so benchmark comparisons should account for the intervening progress.
Context windows are 200k (o3) vs 2M (Grok 4 Fast).
Direct benchmark comparisons are unavailable — o3 and Grok 4 Fast don't publish scores on any of the same benchmarks.