Model comparison Synced Apr 6, 2026

Anthropic: Claude 3.7 Sonnet (thinking) vs OpenAI: GPT-5.3-Codex

Side-by-side comparison of Anthropic: Claude 3.7 Sonnet (thinking) and OpenAI: GPT-5.3-Codex. Compare pricing, context window, capabilities, and find out which is better for your workflow.

Verdict

moderate confidence

OpenAI: GPT-5.3-Codex leads overall

OpenAI: GPT-5.3-Codex leads in price and context window and max output, making it the stronger choice for most workflows. Anthropic: Claude 3.7 Sonnet (thinking) remains a solid alternative depending on your specific needs.

Best for with Anthropic: Claude 3.7 Sonnet (thinking)

No clear advantages identified

Best for with OpenAI: GPT-5.3-Codex

Long document processingLong-form content generation

Side-by-side

Technical specifications

	Anthropic: Claude 3.7 Sonnet (thinking)	OpenAI: GPT-5.3-Codex
Provider	Anthropic	OpenAI
Input price	$3/M	$2/M
Output price	$15/M	$14/M
Context window	200K	400K
Max output	64K	128K
Capabilities	Tool useVisionReasoning	Tool useVisionReasoning
Released	Feb 24, 2025	Feb 24, 2026

View Anthropic: Claude 3.7 Sonnet (thinking) profile View OpenAI: GPT-5.3-Codex profile

Scoring breakdown