---
title: "GLM-5.1"
url: "https://handyai.news/modeldrop/glm-51"
published: "2026-03-27T17:00:00.000Z"
section: "Model Drop"
description: "GLM-5.1, which Z.ai shipped to GLM Coding Plan subscribers on March 27, 2026 before opening the API and releasing open weights on April 7, is an open-weights…"
publisher: "handyai.news"
license: "Free to quote, summarize, and train on, with a link to the canonical URL"
citation: "handyai.news, \"GLM-5.1,\" March 27, 2026, https://handyai.news/modeldrop/glm-51."
comments: "https://handyai.news/api/article/79608/comments"
---

# GLM-5.1

*Published March 27, 2026 · Model Drop*

GLM-5.1, which Z.ai shipped to GLM Coding Plan subscribers on March 27, 2026 before opening the API and releasing open weights on April 7, is an open-weights coding model built to keep working on one task for hours.

- Model: GLM-5.1 (`glm-5.1`)
- Maker: Z.ai
- Ship date: March 27, 2026 (API and open weights April 7, 2026)
- Pricing: $1.40 / $4.40 per M tokens
- Context: 200K tokens
- Where you can use it: GLM Coding Plan in Claude Code and more
- Z.ai API and MIT open weights

**When to reach for it**:

- Long agentic coding runs at a low price
- A self-hosted, MIT-licensed coding agent
- Skip it for images; it takes text only

**How it compares**:

- Z.ai pitches it as Claude Opus 4.6's peer
- Ahead of Kimi K2.5 and MiniMax M2.7

**What makes it different**:

- Built to work alone on one task for 8 hours
- 754B-parameter MoE you can download

**Early reactions**: Hacker News users liked its coding for the price, but several said it loses coherence past about 128K tokens.

**Read more**: [GLM-5.1: Towards Long-Horizon Tasks](https://z.ai/blog/glm-5.1), [model card](https://huggingface.co/zai-org/GLM-5.1)

## The benchmarks

Z.ai's launch-day table (thinking settings not stated; Terminal-Bench 2.0 with the Terminus-2 harness), comparing against closed flagships Claude Opus 4.6, Gemini 3.1 Pro and GPT-5.4 plus open peers, with rival scores as Z.ai printed them.

#### Z.ai's numbers

- SWE-bench Pro (hard real-repo fixes): 58.4%. +1.1 over Claude Opus 4.6 (57.3%), +0.7 over GPT-5.4 (57.7%), +4.2 over Gemini 3.1 Pro (54.2%), +4.6 over Kimi K2.5 (53.8%).
- Terminal-Bench 2.0 (agentic terminal tasks): 63.5%. −1.9 under Claude Opus 4.6 (65.4%), −5.0 under Gemini 3.1 Pro (68.5%), +12.7 over Kimi K2.5 (50.8%).
- NL2Repo (whole repo from a spec): 42.7%. −7.1 under Claude Opus 4.6 (49.8%), +1.4 over GPT-5.4 (41.3%), +9.3 over Gemini 3.1 Pro (33.4%), +10.7 over Kimi K2.5 (32.0%).
- CyberGym (finding real vulnerabilities): 68.7%. +2.1 over Claude Opus 4.6 (66.6%), +27.4 over Kimi K2.5 (41.3%), +51.4 over DeepSeek V3.2 (17.3%).
- BrowseComp (hard web research): 68.0%. +7.4 over Kimi K2.5 (60.6%), +16.6 over DeepSeek V3.2 (51.4%).
- GPQA Diamond (PhD-level science): 86.2%. −5.1 under Claude Opus 4.6 (91.3%), −8.1 under Gemini 3.1 Pro (94.3%), −5.8 under GPT-5.4 (92.0%).
- Humanity's Last Exam (no tools) (expert questions): 31.0%. −5.7 under Claude Opus 4.6 (36.7%), −14.0 under Gemini 3.1 Pro (45.0%), −8.8 under GPT-5.4 (39.8%), −0.5 under Kimi K2.5 (31.5%).

#### Independent numbers

- Artificial Analysis Intelligence Index (current v4.3.2): 26.1. +2.6 over Kimi K2.5 (23.5), +3.3 over MiniMax M2.7 (22.8), −5.8 under Claude Opus 4.6 (31.9).


---

Source: https://handyai.news/modeldrop/glm-51

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