Model comparison - Same provider, successor
GLM-5.1 vs GLM-5.2
GLM-5.1 and GLM-5.2 are both Z.ai models. Both list the same first-party API price: $1.40 per 1M input tokens and $4.40 per 1M output tokens. GLM-5.1 has a 200,000-token context window and GLM-5.2 1,000,000 tokens, and both return up to 128,000 output tokens per response. GLM-5.1 was released on April 7, 2026 and GLM-5.2 on June 16, 2026. Both publish open weights.
Last verified from each provider's pricing page. All sources
Side-by-side specs
| Spec | GLM-5.1 | GLM-5.2 |
|---|---|---|
| Provider | Z.ai | Z.ai |
| Input / 1M tokens | $1.40 | $1.40 |
| Output / 1M tokens | $4.40 | $4.40 |
| Cache read / 1M | $0.26 | $0.26 |
| Context window | 200,000 | 1,000,000 |
| Max output | 128,000 | 128,000 |
| Release date | ||
| Weights | Open | Open |
| License | MIT | MIT |
| API model id | glm-5.1 | glm-5.2 |
| AI Gateway id | zai/glm-5.1 | zai/glm-5.2 |
| Last verified |
Prices in USD per 1M tokens at each provider's standard first-party rate. A dash means the provider does not bill that item separately or no primary page states it.
What each costs in practice
The same three workloads every model page uses, worked from each model's standard list rates. Swap in your own token counts with the math on each model's page.
| Workload | GLM-5.1 | GLM-5.2 |
|---|---|---|
| One agent session1M input tokens and 100K output tokens, no caching. | $1.84 | $1.84 |
| A chat app10,000 requests a day at 2K input and 500 output tokens each. | $50.00$1,500.00 per 30-day month | $50.00$1,500.00 per 30-day month |
| The same session at a 90% cache hit90% of the input is read from the prompt cache. The one-time cache write premium is not included. | $0.814 | $0.814 |
Show the math
GLM-5.1
- One agent sessionInput: 1M x $1.40 = $1.40Output: 0.1M x $4.40 = $0.44
- A chat appInput: 20M x $1.40 = $28.00Output: 5M x $4.40 = $22.00
- The same session at a 90% cache hitCached input: 0.9M x $0.26 = $0.234Uncached input: 0.1M x $1.40 = $0.14Output: 0.1M x $4.40 = $0.44
GLM-5.2
- One agent sessionInput: 1M x $1.40 = $1.40Output: 0.1M x $4.40 = $0.44
- A chat appInput: 20M x $1.40 = $28.00Output: 5M x $4.40 = $22.00
- The same session at a 90% cache hitCached input: 0.9M x $0.26 = $0.234Uncached input: 0.1M x $1.40 = $0.14Output: 0.1M x $4.40 = $0.44
Benchmarks under the same setting
No board in the benchmark directory lists both GLM-5.1 and GLM-5.2 under the same setting, so there is no like-for-like score to show here.
Set them up in your tools
Step-by-step guides whose official docs list GLM-5.1 or GLM-5.2 by model id.
Model pages
FAQ
How do GLM-5.1 and GLM-5.2 compare on price?
Both list the same first-party API price: $1.40 per 1M input tokens and $4.40 per 1M output tokens. For one agent session of 1M input and 100K output tokens with no caching, that is $1.84 on GLM-5.1 and $1.84 on GLM-5.2. Prices are each provider's first-party list rates, verified October 17, 2026 and October 17, 2026.
What are the context windows of GLM-5.1 and GLM-5.2?
GLM-5.1 has a 200,000-token context window and GLM-5.2 1,000,000 tokens, and both return up to 128,000 output tokens per response.
Are GLM-5.1 and GLM-5.2 open weights?
GLM-5.1's weights are published at huggingface.co under the MIT. GLM-5.2's weights are published at huggingface.co under the MIT.
More comparisons
Sources
GLM-5.1 verified from docs.z.ai; GLM-5.2 verified from docs.z.ai. This page is as current as the older of the two: .
- https://docs.z.ai/guides/overview/pricing
- https://docs.z.ai/guides/llm/glm-5.1
- https://docs.z.ai/guides/overview/overview
- https://docs.z.ai/release-notes/new-released
- https://docs.z.ai/openapi.json
- https://huggingface.co/zai-org/GLM-5.1
- https://ai-gateway.vercel.sh/v1/models
- https://docs.z.ai/guides/llm/glm-5.2
- https://huggingface.co/zai-org/GLM-5.2
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