GLM 5.1
GLM 5.1 by Z AI is a flagship agentic engineering model, a MoE built for long-horizon coding and tool use with sustained optimization across long runs.
Model Overview
Capabilities, design details, and architectural traits
GLM 5.1 - Flagship Agentic Engineering Model
GLM-5.1 is Z.ai's next-generation flagship model for agentic engineering: an update to GLM-5 built specifically to stay effective on long-horizon coding and tool-use tasks where earlier models, including GLM-5 itself, tend to plateau.
Defining Characteristics
- Sustained Long-Horizon Optimization: revisits its own reasoning and revises strategy through repeated iteration, sustaining optimization over hundreds of rounds and thousands of tool calls - performance keeps improving the longer it runs.
- DeepSeek Sparse Attention MoE: built on the GLM-5 architecture, which integrates DeepSeek Sparse Attention (DSA).
Why It Exists
Built to fix a specific failure mode in prior models, including GLM-5: exhausting familiar techniques early and plateauing on agentic tasks, regardless of how much time or compute they're given.
Benchmark Performance
Independent evaluations · Artificial Analysis
Accuracy & Capability Details
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Evaluate specifications, pricing, and independent benchmark indices
| Model Details | |||
|---|---|---|---|
| General Info | |||
| Provider | Z AI | Anthropic | Anthropic |
| Release Date | April 7, 2026 | September 22, 2026 | September 28, 2026 |
| Knowledge Cutoff | - | - | Jun 2026 |
| Context & Limits | |||
| Context Window | 203K | 1M Best Context Window | 1M Best Context Window |
| Pricing (per 1M tokens) | |||
| Input Pricing | $1.38 Best Input Pricing | $4 | $2 |
| Output Pricing | $4.40 Best Output Pricing | $20 | $10 |
| Modalities | |||
| Inputs | text | textimagefile | textimagefile |
| Outputs | text | text | text |
| Benchmarks (0-100) | |||
| Intelligence Index | 24.2 | 57.6 Best Intelligence Index | 56.0 |
| Coding Index | - | - | - |
| Agentic Index | - | - | - |
Humanity's Last Exam
Extremely difficult logical reasoning and knowledge.
Long Context Reasoning
Logical reasoning over long context windows.
SciCode Benchmark
Scientific coding and mathematical modeling.
Independent evaluation data provided by Artificial Analysis. To view the latest benchmarks and full details, visit their official site.
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