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

Claude 2.1 vs GLM-4.5

Anthropic
Claude 2.1
Z.ai
GLM-4.5
Overview
CompanyAnthropicZ.ai
Release dateNov 21 2023Jul 28 2025
AccessProprietaryOpen Weight
Specifications
Parameters
355B
Context window
128k
Benchmarks
Coding
SWE-Bench Verified
64.2%
Science
GPQA Diamond
79.1%
Timeline
Release gapClaude 2.1 shipped 615 days before GLM-4.5

Which is better: Claude 2.1 or GLM-4.5?

Claude 2.1 and GLM-4.5 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Claude 2.1 shipped 615 days before GLM-4.5, so benchmark comparisons should account for the intervening progress.

Claude 2.1 is proprietary, while GLM-4.5 is open weight.

Direct benchmark comparisons are unavailable — Claude 2.1 and GLM-4.5 don't publish scores on any of the same benchmarks.

Frequently asked questions

Claude 2.1 was released by Anthropic on Nov 21 2023.

GLM-4.5 was released by Z.ai on Jul 28 2025.

Claude 2.1 is a proprietary model released by Anthropic. GLM-4.5 is an open weight model released by Z.ai.

Other comparisons