Compare AI models

Specifications
ParametersA rough measure of how big the model is. More parameters usually means more capable and more expensive to run, though it is a poor guide on its own — a smaller, newer model often beats a larger, older one.
—744B
Context windowHow much text the model can hold in mind at once — your question, any documents you attach, the conversation so far, and its own reply. Go past it and the earliest part falls out of view.
1M—
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.
$10.00$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.
$50.00$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.
$0.25$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.
$10.00Amazon Bedrock$0.60GMICloud
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
$50.00Amazon Bedrock$1.92GMICloud
$4,500Anthropic list price$216StreamLake · 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.
77%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.
89.1%73.3%
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.
65.6%50.4%
Overview
CompanyAnthropicZ.ai
Release dateSep 1 2026Feb 12 2026
AccessClosedOpen Weight
Model detailsView modelView model

Frequently asked questions

Claude Fable 5.1 leads GLM-5 on 3 of the 3 benchmarks they both report (BullshitBench v2, SWE-Bench Multilingual, Humanity's Last Exam). GLM-5 is cheaper on both input and output: $1.00 vs $10.00 per million input tokens, and $3.20 vs $50.00 per million output tokens. GLM-5 shipped 201 days before Claude Fable 5.1, so benchmark comparisons should account for the intervening progress.

Claude Fable 5.1 is closed, while GLM-5 is open weight.

On BullshitBench v2, Claude Fable 5.1 leads at 77% vs GLM-5 at 28%. On SWE-Bench Multilingual, Claude Fable 5.1 leads at 89.1% vs GLM-5 at 73.3%. On Humanity's Last Exam · with tools, Claude Fable 5.1 leads at 65.6% vs GLM-5 at 50.4%.