Compare AI models
| Specifications | ||
ParametersA rough measure of how big the model is. More parameters usually means more capable and more expensive to run, though it is a poor guide on its own — a smaller, newer model often beats a larger, older one. | 21B | — |
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. | 128k | — |
| 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. | — | $1.00 |
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. | — | $2.00 |
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. | — | $0.20 |
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. | $0.018Darkbloom | — |
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input. | $0.09Darkbloom | — |
| $8.10Darkbloom · fp8 | $300SpaceXSI list price | |
| Benchmarks | ||
SWE-Bench VerifiedCoding — Real coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better. | 60.7% | 70.8% |
Humanity's Last Exam · no toolsMultidisciplinary reasoning — Humanity's Last Exam — extremely hard expert questions across many subjects, written so you can't just look up the answer. “No tools” means the AI answers on its own. Higher is better. | 10.9% | — |
Humanity's Last Exam · with toolsMultidisciplinary reasoning — Humanity's Last Exam — extremely hard expert questions across many subjects. “With tools” means the AI is allowed to search the web or run code while answering. Higher is better. | 17.3% | — |
GPQA DiamondScience — Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 71.5% | — |
MMLUGeneral knowledge — A 57-subject multiple-choice exam — history, law, medicine, maths — that was the standard measure of how much a model knows from 2020 until roughly 2024, when frontier scores crowded into the high 80s and labs moved on to harder tests. The scores here were published years apart under different testing setups, so read them as a historical record rather than a like-for-like ranking. Higher is better. | 85.3% | — |
| Overview | ||
| Company | OpenAI | SpaceXSI |
| Release date | Aug 5 2025 | Aug 28 2025 |
| Access | Open Weight | Closed |
| Model details | View model | View model |
Other comparisons
gpt-oss-20bvsClaude Haiku 5.5Grok Code Fast 1vsClaude Haiku 5.5gpt-oss-20bvsGemini 4 ArgonGrok Code Fast 1vsGemini 4 Argongpt-oss-20bvsMuse Spark OpenGrok Code Fast 1vsMuse Spark Opengpt-oss-20bvsDeepSeek-V4.1-FlashGrok Code Fast 1vsDeepSeek-V4.1-Flashgpt-oss-20bvsMistral Large 4Grok Code Fast 1vsMistral Large 4gpt-oss-20bvsKimi K3Grok Code Fast 1vsKimi K3Frequently asked questions
Grok Code Fast 1 leads gpt-oss-20b on 1 of the 1 benchmark they both report (SWE-Bench Verified). Only Grok Code Fast 1 has a verified first-party API price: $1.00 per million input tokens and $2.00 per million output tokens. No pay-as-you-go API rate is tracked for gpt-oss-20b. gpt-oss-20b shipped 23 days before Grok Code Fast 1, so benchmark comparisons should account for the intervening progress.
gpt-oss-20b is open weight, while Grok Code Fast 1 is closed.
On SWE-Bench Verified, Grok Code Fast 1 leads at 70.8% vs gpt-oss-20b at 60.7%.