z-ai

Z.ai: GLM 5.1

by z-ai No longer free

Last seen as free: May 21, 2026

OpenRouter
Tools Reasoning Long Context

About

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...

Specifications

Context Length 203K
Max Output Tokens 203K
Modality text->text
Input text
Output text
Supported Parameters frequency_penalty, include_reasoning, logit_bias, logprobs, max_tokens, min_p, parallel_tool_calls, presence_penalty, reasoning, reasoning_effort, repetition_penalty, response_format, seed, stop, structured_outputs, temperature, tool_choice, tools, top_k, top_logprobs, top_p
Content Moderation No

Error Rate

Based on feedback reported by Free LLM Router users. Error rate reflects the percentage of requests that encountered issues such as rate limiting, unavailability, or errors. Learn more.

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Model 1h 6h 24h 7d 30d
Z.ai: GLM 5.1 - - - 99.3% 99.3%

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Frequently Asked Questions

Is Z.ai: GLM 5.1 still free to use?

Z.ai: GLM 5.1 is no longer available as a free model on OpenRouter.

What is the context window for Z.ai: GLM 5.1?

Z.ai: GLM 5.1 supports a context window of 203K tokens (202,800 tokens).

What is the maximum output length for Z.ai: GLM 5.1?

Z.ai: GLM 5.1 can generate up to 203K tokens (202,800 tokens) per response.

Does Z.ai: GLM 5.1 support function calling (tools)?

Yes, Z.ai: GLM 5.1 supports function calling / tool use, enabling it to interact with external APIs and services.

Does Z.ai: GLM 5.1 support reasoning?

Yes, Z.ai: GLM 5.1 supports reasoning capabilities, allowing it to show its step-by-step thought process.