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. | 253B | — |
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. | 128k | 256k |
| 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 |
| — | $300SpaceXSI list price | |
| These models have no shared benchmark scores. | ||
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. | — | 70.8% |
LiveCodeBenchCompetitive coding — Coding problems published so recently the AI can't have seen them in training — a contamination-free test of raw programming skill. Higher is better. | 66.3% | — |
GPQA DiamondScience — Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 76% | — |
| Overview | ||
| Company | NVIDIA | SpaceXSI |
| Release date | Apr 8 2025 | Aug 28 2025 |
| Access | Open Weight | Closed |
| Model details | View model | View model |
Other comparisons
Llama Nemotron Ultra 253BvsClaude Haiku 5.5Grok Code Fast 1vsClaude Haiku 5.5Llama Nemotron Ultra 253BvsGPT-6.1 SolGrok Code Fast 1vsGPT-6.1 SolLlama Nemotron Ultra 253BvsGemini 4 ArgonGrok Code Fast 1vsGemini 4 ArgonLlama Nemotron Ultra 253BvsMuse Spark OpenGrok Code Fast 1vsMuse Spark OpenLlama Nemotron Ultra 253BvsDeepSeek-V4.1-Flash-1017Grok Code Fast 1vsDeepSeek-V4.1-Flash-1017Llama Nemotron Ultra 253BvsMistral Large 4Grok Code Fast 1vsMistral Large 4Frequently asked questions
Llama Nemotron Ultra 253B and Grok Code Fast 1 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. 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 Llama Nemotron Ultra 253B. Llama Nemotron Ultra 253B shipped 142 days before Grok Code Fast 1, so benchmark comparisons should account for the intervening progress.
Context windows are 128k (Llama Nemotron Ultra 253B) vs 256k (Grok Code Fast 1). Llama Nemotron Ultra 253B is open weight, while Grok Code Fast 1 is closed.
Direct benchmark comparisons are unavailable — Llama Nemotron Ultra 253B and Grok Code Fast 1 don't publish scores on any of the same benchmarks.