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

GPT-5.1-Codex-Max vs GLM-5.1

OpenAI
GPT-5.1-Codex-Max
Z.ai
GLM-5.1
Overview
CompanyOpenAIZ.ai
Release dateNov 19 2025Apr 7 2026
AccessProprietaryOpen Weight
Specifications
Parameters
744B
Context window
200k
Benchmarks
Agentic terminal coding
Terminal-Bench 2.0
63.5%
Web browsing
BrowseComp
68%
Science
GPQA Diamond
86.2%
Timeline
Release gapGPT-5.1-Codex-Max shipped 139 days before GLM-5.1

Which is better: GPT-5.1-Codex-Max or GLM-5.1?

GPT-5.1-Codex-Max and GLM-5.1 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. GPT-5.1-Codex-Max shipped 139 days before GLM-5.1, so benchmark comparisons should account for the intervening progress.

GPT-5.1-Codex-Max is proprietary, while GLM-5.1 is open weight.

Direct benchmark comparisons are unavailable — GPT-5.1-Codex-Max and GLM-5.1 don't publish scores on any of the same benchmarks.

Frequently asked questions

GPT-5.1-Codex-Max was released by OpenAI on Nov 19 2025.

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

GPT-5.1-Codex-Max is a proprietary model released by OpenAI. GLM-5.1 is an open weight model released by Z.ai.

Other comparisons