AI Recommendation
Should you use GLM-5.1?
GLM-5.1 is listed for chat workloads and supports a 200K context window.
Use it when OpenCode Zen's free tier is enough for evaluation, demos, or light production traffic.
GLM-5.1 Free API on OpenCode Zen
Free API VerifiedStrong GLM coding model for agentic engineering, terminals, and repository generation
Free APIOpenAI compatibleReasoningTool callingJSON modeReasoning
API Details
Copy-ready connection details
Base URL
https://opencode.ai/zen/v1 Model ID
glm-5.1 API format OpenAI Chat Completions
Technical Details
GLM-5.1 specifications
Context window 200K
Max output 131K
Status Online
Family glm
Released Apr 7, 2026
Last updated Apr 7, 2026
Free listing since Sep 19, 2026
Input text
Output text
Capabilities reasoning, tool calling, structured output, temperature control
Open weights Yes
Weights Hugging Face
External benchmark references
| Benchmark | Score | Metric | Date |
|---|---|---|---|
| Artificial Analysis Coding Agent Index | 52.7 | average pass@1 | Not listed |
| SWE-Atlas Codebase QnA | 73.2 | pass@1 | Not listed |
| SWE-Bench Pro | 19.8 | pass@1 | Not listed |
| Terminal-Bench | 65.1 | pass@1 | Not listed |
Best for
- Chat
Strengths & Weaknesses
Strengths
- Long context window
- Reasoning mode listed
- Tool calling support
- Structured JSON output
Watch outs
- Vision support is not listed
Benchmark Overview
Benchmark signals for GLM-5.1
Intelligence General reasoning and instruction following
26.4/100 Coding Programming and code generation
55.8/100 Agentic Tool use and multi-step tasks
25.2/100 Speed Observed generation speed
37 tok/s Context Maximum listed context window
200K Pricing
GLM-5.1 pricing per 1M tokens
Input $1.2 per 1M tokens
Output $4.4 per 1M tokens
Access Available OpenCode Zen
Availability
GLM-5.1 availability by provider
We only found this GLM-5.1 listing on OpenCode Zen in the current catalog. Use the related models section for nearby alternatives.
| Provider | Model listing | Access | Context | API | Limits |
|---|---|---|---|---|---|
| | GLM-5.1 | Free tier | 200K | Native | Varies |
Compare
GLM-5.1 alternatives to consider
| Model | Provider | Context | Access |
|---|---|---|---|
| big-pickle | OpenCode Zen | N/A | Free tier |
| DeepSeek V4 Flash | OpenCode Zen | 1.0M | Check provider |
| MiMo-V2.5 | OpenCode Zen | 1.0M | Free tier |
| Nemotron 3 Ultra 550B A55B | OpenCode Zen | 1.0M | Free tier |
| North Mini Code | OpenCode Zen | 256K | Check provider |
Typical Use Cases
GLM-5.1 use cases
Chat
GLM-5.1 is tagged for chat in this catalog and works with OpenAI-compatible client libraries.
FAQ
GLM-5.1 free API FAQ
Is GLM-5.1 free to use?
GLM-5.1 is listed with free API access on OpenCode Zen, subject to the provider's quota and account policy.
What is the GLM-5.1 model ID?
The model ID shown in this catalog is glm-5.1.
What context window does GLM-5.1 support?
The listed context window is 200K tokens with up to 131K output tokens.
More about GLM-5.1
Free GLM-5.1 API.
For API keys, setup steps, and provider-level limits, see the OpenCode Zen provider page.