GLM 5.3 vs GLM 5.3 Flash

GLM 5.3

$0.85 / task

Wins 1 of 3 benchmarks

GLM 5.3 Flash

$0.28 / task

Wins 2 of 3 benchmarks

Only shared

Humanity's Last Exam?

GLM 5.336.6

GLM 5.3 Flash39.9

Terminal-Bench 4.0?

GLM 5.334.8

GLM 5.3 Flash32.8

AutomationBench-AA?

GLM 5.352

GLM 5.3 Flash60.4

Benchmark	GLM 5.3	GLM 5.3 Flash
Humanity's Last Exam	36.6	39.9
Terminal-Bench 4.0	34.8	32.8
AutomationBench-AA	52	60.4

Specs

Spec	GLM 5.3	GLM 5.3 Flash
Input, per 1M	!$1.40	!$0.15
Output, per 1M	!$4.40	!$0.50
Cost per task?	$0.85	$0.28
Speed, tok/s	92	73
Context	1M	1M
Weights	Open	Open
Released	Aug 2026	Aug 2026
Memory (4-bit)	452 GB	193 GB
Licence	glm-5.3	MIT
Commercial use	Restricted	Allowed
See images	—	✓
Read PDFs	—	Partial
Hear audio	—	—
Watch video	—	✓
Call tools	✓	✓
Force a tool call	—	—
Return strict JSON	✓	✓
Search the web	?	?
Run code	?	?
Use a computer	?	?

What breaks when you switch

GLM 5.3 → GLM 5.3 Flash

Defaults to max · Self-hosted›

The Flash chat template falls back to max reasoning effort for missing or unrecognized values; pass low or high explicitly to reduce effort.

Reasoning cannot be disabled›

Disabling reasoning is unsupported; keep reasoning enabled.

tool_choice auto · Z.ai API›

The first-party chat reference exposes only auto for tool_choice.

Complete unmodified reasoning_content›

Preserved thinking defaults on for Coding Plan and off for the standard API; when enabled, return complete unmodified reasoning_content in its original order to protect quality and cache hits.

Only one stop word›

Only one stop word is supported, so do not rely on a list of alternative stop sequences.

GLM 5.3 Flash → GLM 5.3

Memory (4-bit): 193 GB → 452 GB

No image input