Z.ai: GLM 5.1
Z.ai: GLM 5.1 is designed to process text inputs within an extensive context length of 204,800 tokens and supports reasoning and tools for enhanced functionality. It excels in tasks requiring deep analysis but does not provide structured output. This model should be considered by users needing robust text processing capabilities at a price point of $3.036 per million output tokens and $0.966 per million input tokens, with a blended benchmark score of 75.3 across four independent evaluations. Its performance is solid but may not yet have comprehensive coverage in all areas, making it a practical choice for those focused on specific text-based tasks where the cost-effectiveness balances well with its capabilities.
Benchmark results
Independent, published benchmarks. Blended score 74.8 across 4 benchmarks, last refreshed 2026-07-27. How scoring works →
| Benchmark | Measures | Score |
|---|---|---|
| AI Index | broad capability composite | 66.3 |
| AI Index Coding | software engineering tasks | 92.0 |
| AI Index Agentic | multi-step tool-using tasks | 49.3 |
| EQ-Bench | emotional understanding in dialogue | 75.2 |
- Model ID
- z-ai/glm-5.1
- Vendor
- z-ai
- Released
- April 2026
- Tokenizer
- Other
- Input Modalities
- text
- Output Modalities
- text
- Max Output
- 128,000 tokens
- Tool Calling
- ✓ supported
- Structured Output
- ✓ supported
- Reasoning Mode
- ✓ supported
- Vision
- text only
- Audio
- no
- Moderated
- no
What it costs in practice
Computed from the current $0.97/M input and $3.04/M output rates. Run your own numbers →
| Job | Tokens | Cost |
|---|---|---|
| Summarize a 50-page report | 30k in / 1.5k out | $0.03 |
| Classify 1,000 customer emails | 500k in / 50k out | $0.63 |
| A month of a busy support chatbot | 5M in / 2M out | $10.90 |
Price & spec history
Tracked daily by PicksByModel since 2026-07-17.
| Date | Input /M | Output /M | Context |
|---|---|---|---|
| 2026-07-22 | $0.97 | $3.04 | 204,800 |
| 2026-07-17 | $0.97 | $3.04 | 202,752 |
Category rankings
Where Z.ai: GLM 5.1 places across the 18 categories it ranks in. How we rank →
| # | Category | Score |
|---|---|---|
| #16 | JSON ExtractionData · of 25 ranked | 144 |
| #18 | Regex WritingCode · of 25 ranked | 133 |
| #18 | Marketing CopyWriting · of 25 ranked | 127 |
| #18 | Language TranslationWriting · of 25 ranked | 133 |
| #18 | Standardized Test PrepEducation · of 25 ranked | 127 |
| #18 | Tutoring for KidsPersonal · of 25 ranked | 133 |
| #20 | Trivia & General KnowledgePersonal · of 25 ranked | 119 |
| #21 | Fitness CoachingPersonal · of 25 ranked | 131 |
| #22 | Math TutoringEducation · of 25 ranked | 143 |
| #22 | Dataset AnnotationResearch · of 25 ranked | 141 |
| #23 | Short-Form SummarizationWriting · of 25 ranked | 129 |
| #23 | Email DraftingWriting · of 25 ranked | 125 |
| #23 | Financial AnalysisProfessional · of 25 ranked | 153 |
| #23 | Language LearningEducation · of 25 ranked | 125 |
| #23 | SOP / Process DocsBusiness · of 25 ranked | 133 |
| #23 | Chat CompanionPersonal · of 25 ranked | 129 |
| #23 | Experiment DesignResearch · of 25 ranked | 152 |
| #24 | Data AnalysisData · of 25 ranked | 162 |
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Z.ai: GLM 4.7 Flash
Quick answers
- How much does Z.ai: GLM 5.1 cost?
- $0.97 per million input tokens and $3.04 per million output tokens.
- What is Z.ai: GLM 5.1's context window?
- 204,800 tokens, roughly 307 pages of text in a single request.
- Does Z.ai: GLM 5.1 support tool calling?
- It supports tool calling, structured output, a reasoning mode.
- Can Z.ai: GLM 5.1 process images?
- No, it is text-only on the input side.