Z.ai
GLM 5.1: price, context window and ranking
As of 18 October 2026, GLM 5.1 from Z.ai costs $0.966 per million input tokens and $3.036 per million output tokens on OpenRouter, with a context window of 205K tokens. On the LMArena text leaderboard it ranks 39 with a score of 1,462.4.
- Input price
- $0.966
- Output price
- $3.036
- Context window
- 205K
- LMArena score
- 1,462.4
- Providers
- 13
per 1M tokens
per 1M tokens
tokens
rank 39
uptime 95.6%
Specifications
| Field | Value |
|---|---|
| Provider | Z.ai |
| Input price per 1M tokens | $0.966 |
| Output price per 1M tokens | $3.036 |
| Blended price per 1M tokens (3:1) | $1.4835 |
| Context window | 204,800 |
| Providers serving it | 13 |
| Average uptime, past day | 95.6% |
| LMArena | 1,462.4 (rank 39) |
| Arena score per dollar | 985.8 |
| Added to OpenRouter | 2026-04-07 |
| Modality | text->text |
| OpenRouter model ID | z-ai/glm-5.1 |
Price history
- Input
- Output
| Date | Input | Output |
|---|---|---|
| 2026-10-16 | $0.966 | $3.036 |
| 2026-10-17 | $0.966 | $3.036 |
| 2026-10-18 | $0.966 | $3.036 |
Frequently asked questions
How much does GLM 5.1 cost per million tokens?
GLM 5.1 costs $0.966 per million input tokens and $3.036 per million output tokens on OpenRouter, as of 18 October 2026. At a mix of three parts input to one part output the blended price is $1.4835 per million tokens.
What is the context window of GLM 5.1?
GLM 5.1 has a context window of 205K tokens (204,800 exactly).
How does GLM 5.1 rank on LMArena?
GLM 5.1 is ranked 39 on the LMArena text leaderboard with a score of 1,462.4 from 62,889 votes. The listing used is "glm-5.1".
When was GLM 5.1 released?
OpenRouter lists GLM 5.1 as added on 7 April 2026.
Who provides GLM 5.1?
GLM 5.1 is served by 13 providers on OpenRouter, with average uptime of 95.6% over the past day.
Methodology and sources
The catalogue, prices, context lengths and provider counts come from OpenRouter's public Models API. They are fetched every day at 06:00 Istanbul time and stored as a daily snapshot. Weekly changes are calculated by Oesnada by comparing those snapshots; there is no data before 16 October 2026.
Usage shares are calculated from the daily token totals of OpenRouter's Data API: a model's tokens over the past 7 days divided by all tokens in the same period, including the aggregated long tail outside the top 50. Token counts come from each provider's own tokenizer and are not directly comparable across providers. The data is published by OpenRouter under CC BY 4.0. Variants such as ":free" are counted separately, so shares here can differ from OpenRouter's own ranking page.
Quality rankings come from LMArena's text (overall) leaderboard. A model is matched only when its name matches exactly; if a model has several listings, the highest-scoring one is used. "Frontier" means a model in the LMArena top 15.
"Best value" divides the LMArena score by the blended price (three parts input to one part output). Arena scores are not a linear scale, so the ratio is a rough guide. This page is produced automatically.
- OpenRouter Models API
- OpenRouter Rankings (Data API) (CC BY 4.0)
- LMArena leaderboard dataset (CC BY 4.0)
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Cite this page
Oesnada, "GLM 5.1: price, context window and ranking", https://oesnada.com/ai-models/z-ai-glm-5-1, accessed 18 October 2026.