GLM 5.3 FlashX Legal vs GPT-6 Luna

Price, context window & benchmark comparison

GLM 5.3 FlashX Legal

Z.ai (Zhipu)

$0.37 / $1.25

Input / Output · per 1M tokens

GPT-6 Luna

OpenAI

$0.10 / $0.50

Input / Output · per 1M tokens

Compare different models

Verdict: GPT-6 Luna is 2.9× cheaper than GLM 5.3 FlashX Legal on a typical 3:1 input/output mix. GPT-6 Luna has the larger context window (1.1M vs 1M).

	GLM 5.3 FlashX Legal	GPT-6 Luna
Input price / 1M	$0.37	$0.10
Output price / 1M	$1.25	$0.50
Blended price (3:1)	$0.59	$0.20
Cached input / 1M	$0.075	$0.01
Context window	1M	1.1M
Max output	131K	128K
Intelligence index	—	27.9
Coding index	—	—
Providers	1	8
Best provider uptime (30m)	100.0%	100.0%
Vision input	Yes	Yes
Reasoning	Yes	Yes
Tool calling	Yes	Yes
Released	2026-11-02	2026-09-22
Retirement	—	—

Cost calculator

Input tokens / requestOutput tokens / requestRequests / day

FAQ

Which is cheaper, GLM 5.3 FlashX Legal or GPT-6 Luna?

GPT-6 Luna is 2.9× cheaper than GLM 5.3 FlashX Legal on a typical 3:1 input/output mix.

GLM 5.3 FlashX Legal vs GPT-6 Luna: which has a bigger context window?

GLM 5.3 FlashX Legal: 1,048,576 tokens. GPT-6 Luna: 1,050,000 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-6 Luna ≈ $450.00.

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