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Z.ai

GLM 5.3

Flagship GLM model for long-horizon coding, agents, and complex project delivery

Released
Aug 14 2026
Modality
Text
Context
1M tokens
Price in / cached input / out
$1.35 / $0.26 / $4.25per 1M tokens

Quickstart

OpenAI-compatible: change the base URL, and the setup is complete.

from openai import OpenAI
import os

client = OpenAI(
    base_url="https://api.you.com/v1",
    api_key=os.environ["YOU_API_KEY"],
)

response = client.chat.completions.create(
    model="glm-5.3",
    messages=[{"role": "user", "content": "Summarize this support ticket in two sentences."}],
)

print(response.choices[0].message.content)

Specifications

Technical details, capabilities, pricing, and data handling.

Model info

Input Modality
Text
Output Modality
Text
Context Window
1M
License
GLM-5.3 License

Capabilities

Reasoning
Supported
Function calling
Supported
Structured outputs
Supported
Web search grounding
Not supported

Pricing

Input
$1.35
Cached input
$0.26
Output
$4.25

Data handling

Zero data retention
Supported
No training on customer data
Supported
Regions
US

Providers

Access models through multiple providers with automatic routing and built-in failover.

Providers serving GLM 5.3
ProviderZDRNo trainingRegion
You InferenceYesYes
US
ParasailYesYes
US
WaferYesYes
US

When to use GLM 5.3

Guidance based on the specifications and benchmarks on this page.

Best for

  • Complex, long-horizon agentic codingZ.ai calls GLM-5.3 its most capable open-weights coding model, 50% better than GLM-5.2 on its in-house Code Bench.
  • Security research and vulnerability discoveryZ.ai reports state-of-the-art results on CyberGym (84.5%) and more than double GLM-5.2 on exploitation benchmarks.
  • Tool-driven automation workflowsScores 73.0% on Toolathlon Verified and 62.5% on Humanity's Last Exam with tools.
Get API key

Consider alternatives for

  • You need image understandingGLM-5.3 is text-only; Z.ai's GLM-5.3 Flash is its first natively multimodal GLM-5 model.
  • You need a lighter modelGLM-5.3 Flash is Z.ai's smaller sibling, with 320B total / 18B active parameters.
  • You need top repository-generation scoresOn NL2Repo, Z.ai's own table shows Opus 4.8 well ahead (69.7% vs 58.0%).

Benchmarks

GLM 5.3 results alongside comparable models

Reasoning benchmark scores
BenchmarkGLM 5.3Z.aiDeepSeek V4.1 FlashDeepSeekQwen3.8 MaxAlibabaKimi K3Moonshot AIMuse Spark 1.3MetaDeepSeek V4 ProDeepSeek
Humanity's Last Exam (with tools)62.5%63.9%56.2%56%Not evaluated48.2%

Scores are self-reported by each model’s developer, so settings may vary between models. Sources: GLM 5.3 (Hugging Face), DeepSeek V4.1 Flash (Hugging Face), Qwen3.8 Max (Hugging Face), Qwen3.8 Max (release post), Kimi K3 (Hugging Face), Muse Spark 1.3 (release post), DeepSeek V4 Pro (Hugging Face).

Build with Inference Router

Tell us what you run today, and a solutions engineer will show you what it costs on open-weight models.