Is Claude Opus 4.5 or GPT-5.1-Codex cheaper?

GPT-5.1-Codex is cheaper on output tokens ($10.00 vs $25.00 per 1M).

Which has the larger context window, Claude Opus 4.5 or GPT-5.1-Codex?

GPT-5.1-Codex has the larger context window (400K tokens).

Claude Opus 4.5 vs GPT-5.1-Codex

GPT-5.1-Codex is cheaper on output tokens, while GPT-5.1-Codex offers a larger context window. Choose Claude Opus 4.5 or GPT-5.1-Codex based on the trade-off between cost, context, and the benchmarks that matter for your use case.

Spec	Claude Opus 4.5	GPT-5.1-Codex
Provider	ZenMux	ZenMux
Input / 1M tokens	$5.00	$1.25
Output / 1M tokens	$25.00	$10.00
Context window	200K	400K
Parameters	—	—
Open weights	No	No
Released	Nov 2025	Nov 2025

Claude Opus 4.5 details →GPT-5.1-Codex details →

FAQ

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