GLM 5.1

z-ai/glm-5.1-20260406

Z.ai: GLM 5.1 is a text‑only model from the provider z‑ai that supports reasoning and tool integration, with open weights available. It provides a context length of 202 752 tokens and is priced at $0.966 per million input tokens and $3.036 per million output tokens. The model was released on 2025‑01‑20.

  • tool use
  • structured outputs
  • reasoning
  • open-weight

At a glance

providerz-ai
releasedJan 20, 2025
context205K
input / M$0.97

Specifications

What the API gives you

Context window
205K tokens
Max output
128K tokens
Input price
$0.97 / 1M tokens
Output price
$3.04 / 1M tokens
Cache read
$0.18 / 1M tokens
Modalities
text → text
Knowledge cutoff
—
Released
Jan 20, 2025

Recommendation coverage

Where this model appears

  1. #5Best LLM for Translation
  2. #5Best LLM for Business Writing
  3. #6Best LLM for Everyday Translation

Measured evidence

Public benchmark record

LMArena Agent
1.22026-07-13
LMArena Agent
1.72026-07-20
LMArena Text
1466 Elo2026-07-16
LMArena WebDev
1526 Elo2026-07-16
LMArena WebDev
1525 Elo2026-07-20

LMArena data licensed CC-BY-4.0. Aider (Apache-2.0) and SWE-bench (MIT) are open.

Open-weight model on Hugging Face.

Catalog data via OpenRouter and models.dev. Last checked within the past 6 hours.