Claude Opus 4.8 vs GPT-5.5

Anthropic's Claude Opus 4.8 against OpenAI's GPT-5.5 — price, context and what each is best at. Both are available through one OpenAI-compatible API.

AnyModel — you pay	Claude Opus 4.8	GPT-5.5
Vendor	Anthropic	OpenAI
Input / 1M	$0.4	$0.05
Output / 1M	$0.4	$0.05
Context	1M	1M
Best for	Architecture	Complex coding

Claude Opus 4.8

The current Opus — Anthropic's agentic-coding flagship.

Claude Opus 4.8 leads the Claude 4 line on nuanced reasoning, agentic coding and careful long-form writing, now with a 1M-token context window. The go-to when output quality matters more than cost.

More about Claude Opus 4.8 →

GPT-5.5

OpenAI's flagship for coding, agents and research-grade reasoning.

GPT-5.5 is OpenAI's top general-purpose model and the engine behind modern Codex: state-of-the-art coding, computer use and multi-step reasoning with a ~1M-token window. The default pick when you want one model that handles everything.

More about GPT-5.5 →

Quick take: GPT-5.5 is cheaper on output tokens ($0.05 vs $0.4 per 1M). Compare their strengths and context for your task; you can switch the model id at any time.

FAQ

Which is cheaper, Claude Opus 4.8 or GPT-5.5?

GPT-5.5 is cheaper on output tokens ($0.05 vs $0.4 per 1M).

Which has a larger context window, Claude Opus 4.8 or GPT-5.5?

Claude Opus 4.8: 1M; GPT-5.5: 1M.