GLM 5.1
Z.aiReleased Apr 7, 2026
GLM-5.1 delivers a major leap in coding capability, with particularly significant gains in handling long-horizon tasks. Unlike previous models built around minute-level interactions, GLM-5.1 can work independently and continuously on...
- Context window
- 203K tokens
- Input
- text
- Output
- text
- Tokenizer
- Other
- Released
- Apr 7, 2026
- Reasoning
- optional
Pricing
Per 1M tokens. The provider price and our flat 3% fee are separate columns — what you pay is their sum.
| Per 1M tokens | Provider | + 3% fee | You pay |
|---|---|---|---|
| Input | $0.975 | $0.029 | $1.00 |
| Output | $4.30 | $0.129 | $4.43 |
Benchmarks
Artificial Analysis
- Intelligence index
- 40.2
- Coding index
- 55.8
- Agentic index
- 29.9
Design Arena
| Category | Elo | Win rate | Rank |
|---|---|---|---|
| 3Dmodels | 1343 | 63.9% | #5 |
| ASCII artmodels | 1181 | 49.2% | #31 |
| Codemodels | 1332 | 60.3% | #5 |
| Data vizmodels | 1366 | 67% | #2 |
| Game devmodels | 1339 | 62% | #6 |
| SVGmodels | 1285 | 62.1% | #5 |
| UI componentsmodels | 1340 | 62.5% | #4 |
| Websitesmodels | 1317 | 57.2% | #7 |
| agenticgamedevagents | 1216 | 54.1% | #4 |
| agentichtmlslidesagents | 1205 | 52% | #6 |
| agenticslidesagents | 1245 | 54.4% | #3 |
| agenticslides(html)agents | 1204 | 51.8% | #6 |
| agenticslides(python-pptx)agents | 1240 | 53.3% | #4 |
| androidnativeagents | 1244 | 53.8% | #7 |
| Full-stackagents | 1233 | 56.9% | #8 |
| godotgamedevagents | 1236 | 55.9% | #4 |
| htmlslidesagents | 1206 | 52.7% | #7 |
| Mobile appsagents | 1236 | 55.4% | #7 |
| pptxslidesagents | 1241 | 53.5% | #4 |
| python-pptxslidesagents | 1258 | 54.2% | #3 |
| Web appsagents | 1243 | 55.1% | #10 |
Head-to-head preference voting. How we filter and rank
Supported parameters
- frequency_penalty
- include_reasoning
- logit_bias
- logprobs
- max_tokens
- min_p
- parallel_tool_calls
- presence_penalty
- reasoning
- reasoning_effort
- repetition_penalty
- response_format
- seed
- stop
- structured_outputs
- temperature
- tool_choice
- tools
- top_k
- top_logprobs
- top_p
Call it
OpenAI-compatible: point your SDK at api.openkey.ai/v1 and use model z-ai/glm-5.1.
curl https://api.openkey.ai/v1/chat/completions \
-H "Authorization: Bearer $OPENKEY_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "z-ai/glm-5.1",
"messages": [{"role": "user", "content": "Hello"}]
}'import os
from openai import OpenAI
client = OpenAI(
base_url="https://api.openkey.ai/v1",
api_key=os.environ["OPENKEY_API_KEY"],
)
completion = client.chat.completions.create(
model="z-ai/glm-5.1",
messages=[{"role": "user", "content": "Hello"}],
)
print(completion.choices[0].message.content)import OpenAI from "openai";
const client = new OpenAI({
baseURL: "https://api.openkey.ai/v1",
apiKey: process.env.OPENKEY_API_KEY,
});
const completion = await client.chat.completions.create({
model: "z-ai/glm-5.1",
messages: [{ role: "user", content: "Hello" }],
});
console.log(completion.choices[0].message.content);Questions
- How much does GLM 5.1 cost via API?
- Through OpenKey, GLM 5.1 costs $1.00 per 1M input tokens and $4.43 per 1M output tokens. That is the provider price ($0.975 / $4.30) plus a flat 3% fee — nothing else.
- What is GLM 5.1's context window?
- GLM 5.1 accepts up to 203K tokens of context.
- Is GLM 5.1 OpenAI-compatible?
- Yes. Send requests to OpenKey's /v1/chat/completions endpoint with model "z-ai/glm-5.1" using any OpenAI SDK — only the base URL and API key change.
- What inputs does GLM 5.1 support?
- GLM 5.1 accepts text input and produces text output.
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