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

Grok Code Fast 1 vs GLM-5.1

xAI
Grok Code Fast 1
Z.ai
GLM-5.1
Overview
CompanyxAIZ.ai
Release dateAug 28 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 gapGrok Code Fast 1 shipped 222 days before GLM-5.1

Which is better: Grok Code Fast 1 or GLM-5.1?

Grok Code Fast 1 and GLM-5.1 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Grok Code Fast 1 shipped 222 days before GLM-5.1, so benchmark comparisons should account for the intervening progress.

Grok Code Fast 1 is proprietary, while GLM-5.1 is open weight.

Direct benchmark comparisons are unavailable — Grok Code Fast 1 and GLM-5.1 don't publish scores on any of the same benchmarks.

Frequently asked questions

Grok Code Fast 1 was released by xAI on Aug 28 2025.

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

Grok Code Fast 1 is a proprietary model released by xAI. GLM-5.1 is an open weight model released by Z.ai.

Other comparisons