Compare AI models

Specifications
Parameters
—744B
Context window
1M200k
API pricing
Input price
$10.00$1.40
Output price
$50.00$4.40
Cached input price
$0.25$0.26
Cheapest input
$10.00Amazon Bedrock$0.966StreamLake
Cheapest output
$50.00Amazon Bedrock$3.036StreamLake
Benchmarks
BullshitBench v2
77%22%
Next.js Evals
97%58%
Humanity's Last Exam · with tools
65.6%52.3%
Overview
CompanyAnthropicZ.ai
Release dateSep 1 2026Apr 7 2026
AccessClosedOpen Weight
Model detailsView modelView model

Frequently asked questions

Claude Fable 5.1 leads GLM-5.1 on 3 of the 3 benchmarks they both report (BullshitBench v2, Next.js Evals, Humanity's Last Exam). GLM-5.1 is cheaper on both input and output: $1.40 vs $10.00 per million input tokens, and $4.40 vs $50.00 per million output tokens. GLM-5.1 shipped 147 days before Claude Fable 5.1, so benchmark comparisons should account for the intervening progress.

Context windows are 1M (Claude Fable 5.1) vs 200k (GLM-5.1). Claude Fable 5.1 is closed, while GLM-5.1 is open weight.

On BullshitBench v2, Claude Fable 5.1 leads at 77% vs GLM-5.1 at 22%. On Next.js Evals, Claude Fable 5.1 leads at 97% vs GLM-5.1 at 58%. On Humanity's Last Exam · with tools, Claude Fable 5.1 leads at 65.6% vs GLM-5.1 at 52.3%.