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 | 200k |
| 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. | — | $20.00 |
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. | — | $80.00 |
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. | — | $20.00OpenAI |
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input. | — | $80.00OpenAI |
| — | $8,000OpenAI list price | |
| These models have no shared benchmark scores. | ||
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 | OpenAI |
| Release date | Apr 8 2025 | Jun 10 2025 |
| Access | Open Weight | Closed |
| Model details | View model | View model |
Other comparisons
Llama Nemotron Ultra 253BvsClaude Haiku 5.5o3-provsClaude Haiku 5.5Llama Nemotron Ultra 253BvsGemini 4 Argono3-provsGemini 4 ArgonLlama Nemotron Ultra 253BvsMuse Spark Openo3-provsMuse Spark OpenLlama Nemotron Ultra 253BvsGrok 4.7o3-provsGrok 4.7Llama Nemotron Ultra 253BvsDeepSeek-V4.1-Flash-1017o3-provsDeepSeek-V4.1-Flash-1017Llama Nemotron Ultra 253BvsMistral Large 4o3-provsMistral Large 4Frequently asked questions
Llama Nemotron Ultra 253B and o3-pro don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Only o3-pro has a verified first-party API price: $20.00 per million input tokens and $80.00 per million output tokens. No pay-as-you-go API rate is tracked for Llama Nemotron Ultra 253B. Llama Nemotron Ultra 253B shipped 63 days before o3-pro, so benchmark comparisons should account for the intervening progress.
Context windows are 128k (Llama Nemotron Ultra 253B) vs 200k (o3-pro). Llama Nemotron Ultra 253B is open weight, while o3-pro is closed.
Direct benchmark comparisons are unavailable — Llama Nemotron Ultra 253B and o3-pro don't publish scores on any of the same benchmarks.