What Is GLM? Z.ai Models and Changes to Thinking Mode
GLM is Z.ai’s model family, including hosted APIs and open-weight releases. Using GLM-5.3 and earlier 4.5 and 4.7 releases, this article explains text input, thinking controls and migration differences.
Meet this model
GLM is Z.ai’s generative model family for uses including text reasoning and coding, with applications able to connect it to external tools. It is distinct from Z.ai’s chat app or a coding client. Input types and thinking controls vary significantly by generation: GLM-5.3, for example, accepts text only and cannot disable reasoning. Assess the specific model rather than merely stating “supports GLM.”
Evaluate the model family and coding app separately
A GLM model can generate code or request a function call, but reading a repository and running commands still require an application environment. After integration with a compatible coding client, execution records show which changes actually occurred. A claim that a bug is fixed does not replace a patch and tests, and tool configuration can change the experience across clients.
The GLM-5.3 page checked on October 20, 2026 emphasizes software engineering and longer agent tasks, with a one-million-token context and up to 128K output tokens. It currently accepts text only. An interface screenshot therefore requires a vision model or another way to extract its information; the family brand alone does not guarantee vision support.
Check thinking settings when migrating from older models
GLM-4.5 documentation provides Thinking and Non-Thinking modes controlled through thinking.type. GLM-5.3 instead always reasons and supports low, high and max effort levels. Older code that continues to send disabled will fail. Reducing reasoning effort and turning reasoning off are different operations.
For example, when upgrading a field-extraction program, update the calling configuration before comparing missing-field handling and response time. For complex code changes, try a higher effort level with the same task samples. The following 5.3 configuration fragment shows only the model and thinking fields; it is not a complete standalone HTTP request.
{
"model": "glm-5.3",
"thinking": {"type": "enabled"},
"reasoning_effort": "low"
}Keep open-weight and hosted version instructions separate
The official GLM-4.7 model card provides open weights and local deployment instructions, with an MIT license. It also describes retaining thinking across turns for tasks that repeatedly use tools. Those details belong to the 4.7 release and do not establish identical licensing or parameter behavior for 5.3 or other GLM models.
Self-hosting also needs correct parsing of tool calls and reasoning content. Mixing reasoning with final text can produce an unexpected application format and should not automatically be attributed to model capability. This article reviews official specifications without running GLM benchmarks or presenting the provider’s engineering improvement claims as HotAI.news test results.
Checked sources
These sources support the concepts and methods described here. Examples and test scope are labeled separately; check the version of the tools you use.