Model comparison ยท 2026-09-22
GLM-5.3: reasoning can't be turned off, choosing between low, high, and max
Covers that GLM-5.3 runs reasoning on every response and it cannot be disabled, that LLMTR defaults to the low level, and when you'd want :high or :max for harder tasks.
There's no 'turn reasoning off' option on this model
On some models like GLM-4.6V-FlashX or Qwen3.8-Max, reasoning is a capability that can be toggled on or off. GLM-5.3 is different: its catalog description states directly that reasoning runs on every response and cannot be disabled. Choosing this model means accepting upfront that every request will carry some degree of reasoning cost.
LLMTR calls this model at the low effort level by default when you send a plain request. That's the lightest reasoning depth and keeps latency reasonable; on a hard task, you can request deeper reasoning by appending `:high` or `:max` to the model identifier.
How to choose among the three levels
The low level is sufficient for cases that use the 1M-token context window and function calling but where the task itself doesn't require complex multi-step planning (summarizing a file, explaining a function). The high level gives more consistent results on a coding task needing to trace dependencies across multiple files, or an agent loop that needs to interpret a terminal command's output and decide the next step.
The max level carries the highest latency and reasoning-token cost; it's worth trying only on genuinely complex, long-horizon tasks where low and high fall short. Defaulting to max without comparing all three levels on your own task examples unnecessarily raises latency and cost.
- Low (default): simple summarization, explanation, single-step tasks.
- High: multi-file coding, multi-step agent decisions.
- Max: the most complex, long-horizon tasks; don't use it by default.
Don't try sending image input
GLM-5.3 doesn't accept image input; it's text-only. If a task needs visual understanding, rather than using this model alone, you'd need to convert the visual content to text with a separate vision model first and give that text to GLM-5.3.
Frequently asked questions
Can I turn reasoning off entirely and get a plain response?
No, on this model reasoning runs on every response and cannot be disabled; the lightest option is the low effort level.
Which level does LLMTR use by default?
When you send a plain request, LLMTR calls this model at the low effort level; for deeper reasoning you need to append the :high or :max suffix to the model identifier.