GLM-5.3 vs GPT-5.6 Sol

Both are Flagship-tier models, from Z.ai and OpenAI respectively. GLM-5.3 is the cheaper choice overall at a 4:1 input:output ratio.

Which is cheaper

Input price: GLM-5.3 is cheaper ($1.40 vs $4.00).
Output price: GLM-5.3 is cheaper ($4.40 vs $20.00).
Blended, 4:1 input:output ratio: GLM-5.3 is 72.2% cheaper ($2.00 vs $7.20 per weighted 1M tokens).

Side by side

Spec	GLM-5.3	GPT-5.6 Sol
Provider	Z.ai	OpenAI
Tier	Flagship	Flagship
Context window	1M	1.05M
Max output	128K	128K
Input $/1M	$1.40	$4.00
Output $/1M	$4.40	$20.00
Cache read $/1M	$0.26	$0.40
Cache write $/1M	—	$5.00
Modalities	text	text, image

GLM-5.3. Latest flagship text model, per 1M tokens. Context window not stated on pricing page.

GPT-5.6 Sol. Short-context rate, for prompts up to 272K input tokens. Above 272K the rate is $8 input / $30 output, cache read $0.80, cache write $10 per 1M. Promotional pricing, stated to run at least through 21 November 2026.

Sources

GLM-5.3 — verified August 29, 2026

GPT-5.6 Sol — verified August 29, 2026

Full GLM-5.3 pricing page → · Full GPT-5.6 Sol pricing page →