GLM-5.1: The new open SOTA LLM from Z.ai is 94.6% from Claude Opus 4. 6

On March 27, 2026, Z.ai (formerly Zhipu AI) released the GLM-5.1, the latest iteration of its flagship open model. It is already available to all GLM Coding Plan subscribers and demonstrates results that put it on a par with the top closed-source models. Full open-weights under the MIT license are promised in the coming days (full release is scheduled around April 6).

This is not just another version. GLM-5.1 is the logical continuation of GLM-5 (February 2026), which has already revolutionized the open AI market, moving from “vibe coding” to real agentic engineering. Below is the most complete and only verified analysis based on official sources Z.ai, Hugging Face, benchmarks and announcements.

## 1. What happened before GLM-5.1: GLM-5

** Release date:** 11–12 February 2026 Architecture: Mixture-of-Experts (MoE) Parameters: 744 billion total / ~40 billion active per token Training: 28.5 trillion tokens (up from 23 trillion in GLM-4.5) Context: up to 200K (in individual tests up to 202,752 tokens with tools) License: MIT (fully open) ** Models on HF:** zai-org/GLM-5 and zai-org/GLM-5-FP8 (quantized) Additional: DeepSeek Sparse Attention (DSA) + new slime RL infrastructure

The GLM-5 was the first model that Z.ai explicitly positioned as a transition from Vibe Coding to Agentic Engineering. It is trained entirely on Huawei Ascend’s Chinese chips and optimized for long-term agentic tasks, not just code generation.

**GLM-5 Key Benchmarks (Thinking Mode) **

The GLM-5 has already outperformed almost all open-source models and approached Claude Opus 4.5 and GPT-5.2 in real agentic scenarios.

## 2.GLM-5.1 - What has changed in a month and a half

Date of announcement: March 27, 2026 Access: Immediately for all GLM Coding Plan users (Lite/Pro/Max) Open-source status: confirmed. Z.ai CEO Li Zixuan wrote on March 20, “Don’t panic. GLM-5.1 will be open source.” Full weights under MIT are expected in early April.

The main result (independent test in Claude Code):

• GLM-5.1 - 45.3 points
• Claude Opus 4.6 - 47.9 points
• Difference: total -2.6 points (94.6% of Opus)
• Improvement against GLM-5 in the same test: +28% (from 35.4 to 45.3)

In real-world scenarios, the difference is “almost imperceptible,” especially since the test was conducted in Claude’s “native” environment. The model received improvements in:

• complex multi-step reasoning,
• frontend/backend development,
• long-horizon agentic tasks,
• stability of working with tools.

The specifications of the GLM-5.1 have not yet been publicly disclosed (Z.ai traditionally gives full numbers along with open-weights). It is estimated that this is an evolution of the 744B MoE architecture with even more data and post-training improvements.

## 3. How to use GLM-5.1 today

** Option 1. With the GLM Coding Plan (the easiest) Prices (promo for the first month):

• Lite - $3 (usually $10)
• Pro - $15 (usually $30)

Includes:

• GLM-5.1 (SOTA coding)
• GLM-5, GLM-5-Turbo, GLM-4.7 and older models
• 55+ tokens/sec
• Free MCP tools (Vision, Web Search, Web Reader, Zread)
• Compatible with Claude Code, Cursor, Cline, Kilo Code, OpenCode, Roo Code, Droid, etc.

Setting up in Claude Code (example):

{
  "model": "GLM-5.1",
  "apiKey": "ваш_ключ_из_z.ai",
  "baseUrl": "https://api.z.ai/v1"
}

Variant 2. GLM-5 (already open) Download right now:

• Hugging Face: https://huggingface.co/zai-org/GLM-5
• ModelScope: https://modelscope.cn/models/ZhipuAI/GLM-5

Support for vLLM, SGLang, xLLM, KTransformers. It runs on Huawei Ascend, Moore Threads and other Chinese chips.

Example of launching vLLM (FP8):

vllm serve zai-org/GLM-5-FP8 \
  --tensor-parallel-size 8 \
  --gpu-memory-utilization 0.85 \
  --speculative-config.method mtp

## 4. Why is it important

• Switching from "beautiful code" to real agents. GLM-5/5.1 is specifically tailored for long-horizon tasks: from documentation generation and .docx/.pdf/.xlsx to full-fledged multi-tool workflow.
• Openness. MIT license + support for non-NVIDIA chips = you are not tied to one vendor.
• Price/Quality. Subscription from $3 gives 94.6% of Opus in coding – one of the most profitable options of 2026.
• ** Multilingual and Cyrillic.** Like the entire GLM lineup, the model works perfectly with Russian (unlike many Western open-source models).

## 5. Comparison with major competitors (March 2026)

## Outcome

GLM-5.1 is not just an update. This is the model that makes open AI a truly competitive closed-source flagship in the most challenging field of agentic engineering and professional development. In a couple of weeks, we will have full weights, and then any developer will be able to run it locally or retrain for their tasks.

References to start:

• GLM Coding Plan: https://z.ai/subscribe
• GLM-5 (already open) → https://huggingface.co/zai-org/GLM-5
• Official GLM-5 blog by https://z.ai/blog/glm-5