GLM 5.3 FlashX Legal vs GPT-5 Pro

Price, context window & benchmark comparison

GLM 5.3 FlashX Legal

Z.ai (Zhipu)

$0.37 / $1.25

Input / Output · per 1M tokens

GPT-5 Pro

OpenAI

$15.00 / $120.00

Input / Output · per 1M tokens

Compare different models

Verdict: GLM 5.3 FlashX Legal is 69.9× cheaper than GPT-5 Pro on a typical 3:1 input/output mix. GLM 5.3 FlashX Legal has the larger context window (1M vs 400K).

	GLM 5.3 FlashX Legal	GPT-5 Pro
Input price / 1M	$0.37	$15.00
Output price / 1M	$1.25	$120.00
Blended price (3:1)	$0.59	$41.25
Cached input / 1M	$0.075	—
Context window	1M	400K
Max output	131K	128K
Intelligence index	—	—
Coding index	—	—
Providers	1	—
Best provider uptime (30m)	100.0%	—
Vision input	Yes	Yes
Reasoning	Yes	Yes
Tool calling	Yes	Yes
Released	2026-11-02	2025-10-06
Retirement	—	2026-12-11

Cost calculator

Input tokens / requestOutput tokens / requestRequests / day

FAQ

Which is cheaper, GLM 5.3 FlashX Legal or GPT-5 Pro?

GLM 5.3 FlashX Legal is 69.9× cheaper than GPT-5 Pro on a typical 3:1 input/output mix.

GLM 5.3 FlashX Legal vs GPT-5 Pro: which has a bigger context window?

GLM 5.3 FlashX Legal: 1,048,576 tokens. GPT-5 Pro: 400,000 tokens.

How much would 1 million requests cost?

At 2,000 input + 500 output tokens per request: GLM 5.3 FlashX Legal ≈ $1,365, GPT-5 Pro ≈ $90,000.

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