Model Details
Released
Apr 7, 2026
Context Length
200,000
Max Output
128,000
Modalities
Text
→
Text
Capabilities
Tool use
Structured outputs
Prompt caching
Open weights
Where is GLM 5.1 a perfect fit?
GLM-5.1 is Z.ai’s flagship open-weight model for agentic engineering, designed to autonomously execute complex tasks for hours through planning, coding, testing, evaluation, optimization, and delivery.
- Long-running autonomous coding agents
- Repository-scale software engineering
- Complex debugging and refactoring
- Terminal and CLI-based development
- Performance optimization and benchmarking
- Multi-step tool-driven workflows
- Large codebase analysis
- Autonomous research and technical investigation
- Front-end and artifact generation
- Agent systems requiring sustained execution
GLM-5.1's defining feature is sustained autonomous execution rather than simply stronger single-turn reasoning. Z.ai specifically designed it to maintain a goal across extended coding sessions, repeatedly test and evaluate its work, and optimize toward a production-ready result.
- Long-running autonomous coding agents
- Repository-scale software engineering
- Complex debugging and refactoring
- Terminal and CLI-based development
- Performance optimization and benchmarking
- Multi-step tool-driven workflows
- Large codebase analysis
- Autonomous research and technical investigation
- Front-end and artifact generation
- Agent systems requiring sustained execution
GLM-5.1's defining feature is sustained autonomous execution rather than simply stronger single-turn reasoning. Z.ai specifically designed it to maintain a goal across extended coding sessions, repeatedly test and evaluate its work, and optimize toward a production-ready result.
Quick Model Estimate
Your GLM 5.1 Cost Estimate
💰 Total Cost
—
for 1000 input + 1000 output tokens
📥 Input (1000 × $1.400000)
—
📤 Output (1000 × $4.400000)
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Cost Breakdown
📥 Input
📤 Output
Prices updated daily from official provider data.
Pricing
FAQs about GLM 5.1
How much does GLM 5.1 cost per 1M tokens?
GLM 5.1 costs $1.40 per million input tokens, and $4.40 per million output tokens.
What does a typical workload cost with GLM 5.1?
1,000 requests of 2,000 input and 500 output tokens each — 2,000,000 input and 500,000 output tokens in total — costs $5.00 with GLM 5.1 at its lowest rates. Use the calculator on this page for your own volumes.
Where can I use GLM 5.1?
GLM 5.1 is available through Z.ai, from $1.40 per million input tokens.
What is GLM 5.1's context window?
GLM 5.1 has a context window of 200,000 tokens, and returns up to 128,000 tokens in a single response.
What input types does GLM 5.1 support?
GLM 5.1 accepts text input, and returns text.