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.
—744B
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.
1.05M200k
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.
$5.00$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.
$30.00$3.20
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.
$0.50$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.
$2.50OpenAI$0.60GMICloud
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
$15.00OpenAI$1.92GMICloud
$2,500OpenAI list price$216GMICloud · fp8
Benchmarks
BullshitBench v2Nonsense detection — Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better.
47%28%
SWE-Bench MultilingualMultilingual coding — Like SWE-Bench, but the coding problems span many programming languages, not just one. Tests how broadly the AI can code. Higher is better.
77.8%73.3%
Terminal-Bench 2.0Agentic terminal coding — Can the AI work in a command-line terminal — running commands and finishing technical setup tasks the way a developer would? (Version 2.0 of the test.) Higher is better.
82.7%56.2%
BrowseCompWeb browsing — Can the AI browse the web and track down hard-to-find answers? Higher is better.
84.4%75.9%
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.
52.2%50.4%
GPQA DiamondScience — Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better.
93.6%86%
Overview
CompanyOpenAIZ.ai
Release dateApr 23 2026Feb 11 2026
AccessClosedOpen Weight
Model detailsView modelView model

Frequently asked questions

GPT-5.5 leads GLM-5 on 6 of the 6 benchmarks they both report. GLM-5 is cheaper on both input and output: $1.00 vs $5.00 per million input tokens, and $3.20 vs $30.00 per million output tokens. Figures are base-tier rates. GLM-5 shipped 71 days before GPT-5.5, so benchmark comparisons should account for the intervening progress.

Context windows are 1.05M (GPT-5.5) vs 200k (GLM-5). GPT-5.5 is closed, while GLM-5 is open weight.

On BullshitBench v2, GPT-5.5 leads at 47% vs GLM-5 at 28%. On SWE-Bench Multilingual, GPT-5.5 leads at 77.8% vs GLM-5 at 73.3%. On Terminal-Bench 2.0, GPT-5.5 leads at 82.7% vs GLM-5 at 56.2%. On BrowseComp, GPT-5.5 leads at 84.4% vs GLM-5 at 75.9%. On Humanity's Last Exam · with tools, GPT-5.5 leads at 52.2% vs GLM-5 at 50.4%. On GPQA Diamond, GPT-5.5 leads at 93.6% vs GLM-5 at 86%.