Is OpenAI: GPT-5.1-Codex or Anthropic: Claude Opus 4.5 cheaper?

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

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

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

OpenAI: GPT-5.1-Codex vs Anthropic: Claude Opus 4.5

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

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

OpenAI: GPT-5.1-Codex details →Anthropic: Claude Opus 4.5 details →

FAQ

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