Is GPT-5.3 Chat (latest) or Claude Sonnet 4.5 cheaper?

GPT-5.3 Chat (latest) is cheaper on output tokens ($14.00 vs $15.00 per 1M).

Which has the larger context window, GPT-5.3 Chat (latest) or Claude Sonnet 4.5?

Claude Sonnet 4.5 has the larger context window (200K tokens).

GPT-5.3 Chat (latest) vs Claude Sonnet 4.5

GPT-5.3 Chat (latest) is cheaper on output tokens, while Claude Sonnet 4.5 offers a larger context window. Choose GPT-5.3 Chat (latest) or Claude Sonnet 4.5 based on the trade-off between cost, context, and the benchmarks that matter for your use case.

Spec	GPT-5.3 Chat (latest)	Claude Sonnet 4.5
Provider	Merge Gateway	Merge Gateway
Input / 1M tokens	$1.75	$3.00
Output / 1M tokens	$14.00	$15.00
Context window	128K	200K
Parameters	—	—
Open weights	No	No
Released	Mar 2026	Sep 2025

GPT-5.3 Chat (latest) details →Claude Sonnet 4.5 details →

FAQ

Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.