Z.ai: GLM 5.1
Analysis Summary
GLM 5.1 is Z.ai's previous-generation flagship, with an intelligence index of 40.2 and a coding index of 55.8. The agentic index of 70.4 is among the strongest in the field for its intelligence tier, and instruction following benchmarks are high. Tool use and function calling are supported, making it a capable choice for multi-step automation pipelines.
For businesses, GLM 5.1 suits coding assistance, agentic workflows, and structured content tasks. The absence of vision support is a limitation for multimodal use cases, and it has since been superseded by GLM 5.2 within the Z.ai family. The 202K context window is adequate for most document analysis tasks.
At $0.966 input and $3.036 output per million tokens, pricing is reasonable for its capability tier. Teams already using Z.ai infrastructure may find it a cost-effective option, but new adopters should evaluate GLM 5.2 first.
Assessed July 10, 2026
Editorial notes
GLM 5.1 from Z.ai delivers strong coding, a high agentic index of 70.4, and reliable instruction following at competitive pricing, though it lacks vision support.
Rankings consider pricing, capabilities, benchmarks, and real-world applicability and are refreshed as new models launch. Feedback?
DFO Verdict
GLM 5.1 from Z.ai delivers strong coding, a high agentic index of 70.4, and reliable instruction following at competitive pricing, though it lacks vision support.
Benchmark scores
Magenta = intelligence · Ink = technical/agentic · Cyan = content & long-context · Grey = community benchmarks. Data: Artificial Analysis, Hugging Face.
40.2 Intelligence Index·55.8 Coding Index·29.9 Agentic Index
How Z.ai: GLM 5.1 compares
Z.ai: GLM 5.1 ranks #36 of 398 AI models we track for overall intelligence, #35 of 173 for coding, #41 of 154 for agentic tasks. Its 205K-token context window is larger than 61% of the models we list. At $0.95 per million input tokens it is cheaper than 27% 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 content. 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 | $0.95 | $0.000952 |
| Output | $2.99 | $0.002992 |
What would Z.ai: GLM 5.1 cost your business?
Pick the job that looks most like yours, then fine-tune with the sliders. Estimates update live.
A website chatbot handling around 100 customer conversations a day, a few short messages each.
Full calculator with 654 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 $0.95 per million input tokens and $2.99 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 #35 of 173 models, placing it in the top quartile 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.
