GLM 5.3 FlashX Legal vs Sonar Reasoning Pro

Price, context window & benchmark comparison

GLM 5.3 FlashX Legal

Z.ai (Zhipu)

$0.37 / $1.25

Input / Output · per 1M tokens

Sonar Reasoning Pro

Perplexity

$2.00 / $8.00

Input / Output · per 1M tokens

Compare different models

Verdict: GLM 5.3 FlashX Legal is 5.9× cheaper than Sonar Reasoning Pro on a typical 3:1 input/output mix. GLM 5.3 FlashX Legal has the larger context window (1M vs 128K).

	GLM 5.3 FlashX Legal	Sonar Reasoning Pro
Input price / 1M	$0.37	$2.00
Output price / 1M	$1.25	$8.00
Blended price (3:1)	$0.59	$3.50
Cached input / 1M	$0.075	—
Context window	1M	128K
Max output	131K	115K
Intelligence index	—	—
Coding index	—	—
Providers	1	—
Best provider uptime (30m)	100.0%	—
Vision input	Yes	Yes
Reasoning	Yes	Yes
Tool calling	Yes	No
Released	2026-11-02	2025-03-07
Retirement	—	—

Cost calculator

Input tokens / requestOutput tokens / requestRequests / day

FAQ

Which is cheaper, GLM 5.3 FlashX Legal or Sonar Reasoning Pro?

GLM 5.3 FlashX Legal is 5.9× cheaper than Sonar Reasoning Pro on a typical 3:1 input/output mix.

GLM 5.3 FlashX Legal vs Sonar Reasoning Pro: which has a bigger context window?

GLM 5.3 FlashX Legal: 1,048,576 tokens. Sonar Reasoning Pro: 128,000 tokens.

How much would 1 million requests cost?

At 2,000 input + 500 output tokens per request: GLM 5.3 FlashX Legal ≈ $1,365, Sonar Reasoning Pro ≈ $8,000.

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