AI Model Release Tracker - Timeline of Major AI Models from 2022-2026

Claude Opus 4.1 vs GLM-5.1

Anthropic
Claude Opus 4.1
Z.ai
GLM-5.1
Overview
CompanyAnthropicZ.ai
Release dateAug 5 2025Apr 7 2026
AccessProprietaryOpen Weight
Specifications
Parameters
744B
Context window
200k
Benchmarks
Nonsense detection
BullshitBench v2
43%
Coding
SWE-Bench Verified
74.5%
Agentic terminal coding
Terminal-Bench 2.0
63.5%
Web browsing
BrowseComp
68%
Science
GPQA Diamond
80.9%
86.2%Best
Timeline
Release gapClaude Opus 4.1 shipped 245 days before GLM-5.1

Which is better: Claude Opus 4.1 or GLM-5.1?

GLM-5.1 leads Claude Opus 4.1 on 1 of the 1 benchmark they both report (GPQA Diamond). Claude Opus 4.1 shipped 245 days before GLM-5.1, so benchmark comparisons should account for the intervening progress.

Claude Opus 4.1 is proprietary, while GLM-5.1 is open weight.

On GPQA Diamond, GLM-5.1 leads at 86.2% vs Claude Opus 4.1 at 80.9%.

Frequently asked questions

Claude Opus 4.1 was released by Anthropic on Aug 5 2025.

GLM-5.1 was released by Z.ai on Apr 7 2026.

GLM-5.1 leads on GPQA Diamond — Claude Opus 4.1 80.9% vs GLM-5.1 86.2%.

Claude Opus 4.1 is a proprietary model released by Anthropic. GLM-5.1 is an open weight model released by Z.ai.

Other comparisons