Review a code change with GLM 5.3
Give GLM 5.3 a patch, the surrounding code and the behavior you need to preserve. Ask for concrete failure cases and tests before accepting its suggestions.
Prepare a GLM 5.3 reviewGLM 5.3 — Reasoning, Coding & a Playground to Prepare
Explore GLM 5.3 for code review, long documents and tool workflows. Prepare a request here, then continue on SeedRouter to check access and run it.
GLM 5.3 service belongs on SeedRouter. reAPI provides this guide and request editor, not model access, API keys or billing.
GLM 5.3 playground
Prepare a GLM 5.3 request with SeedRouter’s three request formats. Edit parameters locally, inspect the JSON, then continue on SeedRouter.
POST /v1/chat/completions · SeedRouter
Your GLM 5.3 request
Request preview only. Edit nested options as JSON; additional fields stay in the request.
{
"model": "glm-5.3",
"do_sample": true,
"stream": false,
"thinking": {
"type": "enabled",
"clear_thinking": true
},
"reasoning_effort": "max",
"temperature": 1,
"top_p": 0.95,
"tool_stream": false,
"tool_choice": "auto",
"messages": [
{
"role": "user",
"content": "Review a proposed checkout retry policy. Identify where duplicate charges could occur, explain the tradeoffs, and suggest three tests before release."
}
]
}Run GLM 5.3 on SeedRouter
Copy the JSON, open SeedRouter, and paste it into the same request format when GLM 5.3 is available. reAPI does not submit or bill this model.
This link opens the GLM 5.3 page on SeedRouter. Check current access and service terms there before submitting.
What is GLM 5.3?
GLM 5.3 is Z.ai’s text reasoning model for complex software engineering and agent tasks, officially styled GLM-5.3. Z.ai documents a one-million-token context window and up to 128K output tokens, with reasoning always enabled. This page helps you choose a task, understand the changes from GLM 5.2 and prepare a request for SeedRouter; it does not provide a reAPI endpoint.
What you can build with this model
Real-world workflows and production use cases you can build and ship with this model.
Read across long documents with GLM 5.3
Use GLM 5.3 to work through supplied specifications, contracts or research notes as text. Ask it to connect requirements, identify conflicting passages and cite the excerpts behind its answer.
Plan a tool workflow with GLM 5.3
Prepare GLM 5.3 with function descriptions and a clear stopping condition for a task such as locating a failed deployment. Your application executes the requested functions and returns their results.
Prepare GLM 5.3 for your workflow
Reasoning on every request
Choose low, high or max effort for GLM 5.3; max is the documented default. Low reduces the requested effort without turning reasoning off.
Three request formats
Prepare Chat Completions, Responses or Messages requests using the corresponding SeedRouter contract. Each format keeps its own fields and conversation structure.
Keep your request intact
Inspect and copy the complete JSON request before leaving this page. The editor preserves additional fields you supply in JSON mode.
Prepare GLM 5.3 in three steps
- step 01
Choose your request format
Start with Chat Completions, Responses or Messages in the playground. The initial prompt is a code-review example you can replace with your own text. Documented defaults are prefilled; the Messages output limit is an editable example value.
Open - step 02
Review the request
Edit the fields or use JSON mode for the complete request. Keep conversation content and function definitions in their expected structures. Copy the request when it is ready, including any extra fields your client needs.
Open - step 03
Continue on SeedRouter
Open the GLM 5.3 page on SeedRouter and check access for your account. Select the same request format and paste your JSON into its editor. Submission, results and charges happen there; nothing runs automatically from this page.
Open
Capabilities
GLM 5.3 text input
Supply code, questions and documents as text. The flagship GLM 5.3 is documented as text-only; do not assume it accepts the image or video inputs of another GLM variant.
GLM 5.3 long context
Z.ai documents 1M context and a 128K maximum output. Keep the source passages relevant and ask for specific evidence so you can check an answer against the original material.
GLM 5.3 reasoning effort
The documented effort choices are low, high and max. GLM 5.3 keeps thinking enabled, so an older request that disables thinking needs review before migration.
GLM 5.3 function calling
Define functions your application can execute, then inspect the returned tool requests. Function calling describes the model interface; it does not make your application’s tools run by themselves.
GLM 5.3 streaming
Streaming is documented for incremental responses. Inspect the result structure for your chosen protocol, including any separate reasoning, answer text and tool-call events.
GLM 5.3 structured text
Chat requests offer text or JSON-object output. Request a clear shape and validate it in your application; JSON mode alone is not a promise of strict JSON Schema enforcement.
Frequently asked questions
Common questions about this model.
No. This GLM 5.3 page provides information and a local request editor.
GLM 5.3 vs GLM 5.2
Compare documented changes before migrating a request. GLM 5.3 is not simply a larger-context version: both models publish the same capacity headline, while their thinking controls differ.
Decision point
GLM 5.3
GLM 5.2
Model lineage
Updated post-training on the same base
Earlier base in this comparison
Input and output
Text input and text output
Text input and text output
Context capacity
1M tokens, documented by Z.ai
1M tokens, documented by Z.ai
Maximum output
128K tokens
128K tokens
Thinking control
Always enabled
Can be disabled
Reasoning effort
low / high / max; default max
Earlier aliases map to different effort levels
Based on Z.ai documentation checked October 29, 2026. This compares model specifications, not measured performance or reAPI service availability. GLM 5.3 access is directed to SeedRouter.
SeedRouter
Take your GLM 5.3 request to SeedRouter
Prepare your prompt here, keep a copy of the JSON, and check GLM 5.3 access on SeedRouter. That is where account setup, model execution and usage belong.