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.
—320B
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.
400k1M
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.
$1.25—
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.
$10.00—
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.
$0.125—
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.
$0.625OpenAI$0.048OpenInference
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
$5.00OpenAI$0.20OpenInference
$750OpenAI list price$19.60OpenInference · fp4
These models have no shared benchmark scores.
Overview
CompanyOpenAIZ.ai
Release dateNov 12 2025Aug 26 2026
AccessClosedOpen Weight
Model detailsView modelView model

Frequently asked questions

GPT-5.1 and GLM-5.3-Flash don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Only GPT-5.1 has a verified first-party API price: $1.25 per million input tokens and $10.00 per million output tokens. No pay-as-you-go API rate is tracked for GLM-5.3-Flash. GPT-5.1 shipped 287 days before GLM-5.3-Flash, so benchmark comparisons should account for the intervening progress.

Context windows are 400k (GPT-5.1) vs 1M (GLM-5.3-Flash). GPT-5.1 is closed, while GLM-5.3-Flash is open weight.

Direct benchmark comparisons are unavailable — GPT-5.1 and GLM-5.3-Flash don't publish scores on any of the same benchmarks.