GLM-5.3 API

zhipu/glm-5.3
GLM-5.3 is Zhipu AI's newest flagship model, offering a 1M-token context window with deep, tunable reasoning and full parallel tool-calling support for building advanced agents.
Context
1000K tokens
Input
$1.82 / 1M tokens
Output
$5.72 / 1M tokens
Released
Aug 17, 2026

Overview

What Is GLM-5.3 API?

GLM-5.3 is Zhipu AI's newest flagship large language model, built for advanced text generation and deep reasoning. It carries forward the GLM series' full 1M-token context window and adds native, parallel tool/function calling with strict JSON schema output, making it a solid base for agentic applications that need to hold a lot of context and act on it reliably.

Technical Reference

Developer Zhipu AI
Model ID zhipu/glm-5.3
Release Date August 17, 2026
Context Window 1,024,000 tokens (~1M)
Max Output Tokens 131,072
Modalities Text (input and output)
Capabilities Reasoning, parallel tool/function calling, streaming, structured (JSON schema) output

What GLM-5.3 Brings to the Table

The headline spec is the context window: at just over 1,000,000 tokens, GLM-5.3 can hold large documents, long conversation histories, or sizeable codebases in a single request without needing to chunk or summarize first.

Deep, controllable reasoning

GLM-5.3 supports chain-of-thought style reasoning for complex, multi-step problems, alongside faster inference for simpler queries — letting you balance latency and depth depending on the task.

Parallel tool calling with structured output

The model can call multiple tools/functions in a single turn and return responses that strictly conform to a provided JSON schema, which is useful for building reliable agents and structured data pipelines rather than free-form text you have to parse yourself.

Streaming support

Responses can be streamed token-by-token, keeping latency low for chat-style interfaces even on long-context requests.

API Pricing

  • Input: $1.82 per 1M tokens
  • Output: $5.72 per 1M tokens

Where GLM-5.3 Makes the Most Sense

Long-document and long-conversation reasoning

With a 1M-token window, GLM-5.3 can process long reports, transcripts, or multi-file context in one pass instead of splitting the input across multiple calls.

Agentic workflows with tool calling

Parallel function calling plus structured JSON output make GLM-5.3 a practical choice for agents that need to call several tools per turn and return machine-readable results.

Structured data extraction

The strict JSON schema output mode is well suited to extracting structured fields from unstructured text at scale, without post-processing free-form responses.

Uptime and performance

  • Uptime (24h): 100%
  • Uptime (7d): 99.0%
  • Availability (24h): 100%
  • Error rate (24h): 0%
  • End-to-end latency (24h median): 330.5s
  • Time to first token (24h median): 2.8s
  • Throughput (24h median): 40.5 tok/s

Measured on the AI/ML API gateway across live traffic. Figures are medians unless stated. Last updated 2026-10-12.

Use cases

Software engineering and coding workflows are a documented fit for GLM 5.3, including complex software engineering, repo-scale coding, and agentic development tasks.

Long-horizon agent tasks are another stated use case, with the model described as suited to multi-step, tool-driven workflows that need to stay coherent over long contexts.

Cybersecurity work is also explicitly mentioned as a target use case, including “emergent cyber capabilities” and cybersecurity scenarios.

Structured generation and analysis are documented uses as well, including structured outputs, analysis, and long-form text handling in development workflows.

How to use GLM-5.3 API

Install any OpenAI-compatible SDK, point it at api.aimlapi.com/v1, and set the model to zhipu/glm-5.3.

import requests

r = requests.post(
   "https://api.aimlapi.com/v1/chat/completions",
   headers={"Authorization": "Bearer " + AIMLAPI_KEY},
   json={
     "model": "zhipu/glm-5.3",
     "messages": [
       {
         "role": "user",
         "content": "Hello!"
       }
     ]
   },
)
print(r.json())

const r = await fetch("https://api.aimlapi.com/v1/chat/completions", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "zhipu/glm-5.3",
    "messages": [
      {
        "role": "user",
        "content": "Hello!"
      }
    ]
  }),
});
console.log(await r.json());
curl -X POST https://api.aimlapi.com/v1/chat/completions \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"zhipu/glm-5.3","messages":[{"role":"user","content":"Hello!"}]}'

OpenAI-compatible — swap the base URL and it works with your existing SDK.

GLM-5.3 API Pricing

TypePrice
Input
$1.82 / 1M tokens
Output
$5.72 / 1M tokens
Cached input
$0.338 / 1M tokens

GLM-5.3 Benchmarks

BenchmarkScoreWhat it measuresSourceRetrieved
Intelligence
44.9
Composite score across standardised reasoning, knowledge and problem-solving evaluations, measured independently by Artificial AnalysisSourceSeptember 12, 2026
Coding
74.8
Composite score across standardised coding evaluations, measured independently by Artificial AnalysisSourceSeptember 12, 2026

GLM-5.3 vs other models

ModelInputOutputContextBest for
GLM-5.3
This page
$1.82 / 1M tokens
$5.72 / 1M tokens
1000K tokens
Reasoning + agents
$6.5 / 1M tokens
$39 / 1M tokens
1M tokens
Reasoning + agents
$2.6 / 1M tokens
$13 / 1M tokens
1M tokens
Balanced coding + agents
$3.9 / 1M tokens
$19.5 / 1M tokens
1M tokens
Long-context, multimodal & agentic workflows
$1.95 / 1M tokens
$11.7 / 1M tokens
1M tokens
Reasoning + agents

Frequently asked questions

GLM-5.3 has a 1,024,000 tokens context window and can return up to 131,072 tokens.

GLM-5.3 takes text as input and returns text.

Use zhipu/glm-5.3 as the model id. Requests go to https://api.aimlapi.com/v1/chat/completions.

GLM-5.3 became available on August 17, 2026.

GLM-5.3 is priced at input $1.82 / 1M tokens, output $5.72 / 1M tokens, cached input $0.338 / 1M tokens.

Yes, GLM-5.3 can stream responses as they are generated.

GLM-5.3 was built by Zhipu AI.

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