Z.ai: GLM 5.1
Analysis Summary
GLM 5.1 is a Z.ai text model with a 204.8K context window, strong coding capability, tool use, and function calling. Its coding results are substantially stronger than its general reasoning profile, while instruction following and long-context performance support structured technical work.
It is well suited to software implementation, technical SEO, code review, extraction, and constrained tool-connected automation. Moderate input and output pricing make it practical for regular workloads, particularly where code quality matters more than nuanced creative writing. Agentic performance is useful but not exceptional, so autonomous processes should use explicit state tracking, tests, and approval points. Adopt it as a coding and automation specialist, with a more capable reasoning model reserved for strategy, ambiguous briefs, and high-stakes client communication.
Assessed September 7, 2026
Editorial notes
GLM 5.1 delivers strong coding, long context, tool use, and function calling at moderate pricing; its general reasoning is less advanced, so it is better as a technical and automation specialist than a flagship writer.
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DFO Verdict
GLM 5.1 delivers strong coding, long context, tool use, and function calling at moderate pricing; its general reasoning is less advanced, so it is better as a technical and automation specialist than a flagship writer.
Benchmark scores
Magenta = intelligence · Ink = technical/agentic · Cyan = content & long-context · Grey = community benchmarks. Data: Artificial Analysis, Hugging Face.
26.4 Intelligence Index·55.8 Coding Index·25.2 Agentic Index
How Z.ai: GLM 5.1 compares
Z.ai: GLM 5.1 ranks #87 of 437 AI models we track for overall intelligence, #62 of 209 for coding, #69 of 191 for agentic tasks. Its 205K-token context window is larger than 55% of the models we list. At $0.97 per million input tokens it is cheaper than 28% of comparable models.
Dark bar = input · light bar = output, scaled to the priciest peer.
1M tokens ≈ 8 full-length novels or ~2,500 pages of business documents in a single request.
Strongest on business fit. The pulled-in intelligence corner is the trade-off, and if the shape matters more than the price, this is your model.
Compare shapes side-by-side →Pricing
| Token Type | Cost per 1M tokens | Cost per 1K tokens |
|---|---|---|
| Input | $0.97 | $0.000966 |
| Output | $3.04 | $0.003036 |
What would Z.ai: GLM 5.1 cost your business?
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A website chatbot handling around 100 customer conversations a day, a few short messages each.
Full calculator with 772 models → Price Calculator
These numbers get smaller with the right architecture.
We route routine calls to cheap models and save Z.ai: GLM 5.1 for the hard ones. Most clients cut their estimate by 60-80%.
Talk to our teamAbout Z.ai: GLM 5.1
GLM-5.1 delivers a major leap in coding capability, with particularly significant gains in handling long-horizon tasks. Unlike previous models built around minute-level interactions, GLM-5.1 can work independently and continuously on..
Frequently asked questions about Z.ai: GLM 5.1
How much does Z.ai: GLM 5.1 cost?
Z.ai: GLM 5.1 costs $0.97 per million input tokens and $3.04 per million output tokens.
What is the context window of Z.ai: GLM 5.1?
Z.ai: GLM 5.1 has a context window of 204,800 tokens (205K).
Is Z.ai: GLM 5.1 good for coding?
On our coding benchmark index, Z.ai: GLM 5.1 ranks #62 of 209 models, placing it in the broader range of the field for code generation and debugging.
What can Z.ai: GLM 5.1 do?
Z.ai: GLM 5.1 supports tool use and function calling.
Who created Z.ai: GLM 5.1?
Z.ai: GLM 5.1 is developed by Z.ai and was released on April 7, 2026.