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.
128k200k
API pricingUSD per 1M tokens · lower wins
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.
—$1.10OpenAI
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
—$4.40OpenAI
—$440OpenAI
These models have no shared benchmark scores.
Overview
CompanyNVIDIAOpenAI
Release dateApr 8 2025Apr 16 2025
AccessOpen WeightClosed
Model detailsView modelView model

Frequently asked questions

Llama Nemotron Ultra 253B and o4-mini-high don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Llama Nemotron Ultra 253B shipped 8 days before o4-mini-high, so benchmark comparisons should account for the intervening progress.

Context windows are 128k (Llama Nemotron Ultra 253B) vs 200k (o4-mini-high). Llama Nemotron Ultra 253B is open weight, while o4-mini-high is closed.

Direct benchmark comparisons are unavailable — Llama Nemotron Ultra 253B and o4-mini-high don't publish scores on any of the same benchmarks.