Claude Opus 4.8 vs GPT-5.6 Sol

Anthropic's Claude Opus 4.8 against OpenAI's GPT-5.6 Sol — price, context and what each is best at. Both are available through one OpenAI-compatible API.

AnyModel — you pay	Claude Opus 4.8	GPT-5.6 Sol
Vendor	Anthropic	OpenAI
Input / 1M	$0.2	$0.1
Output / 1M	$0.2	$0.1
Context	1M	400K
Best for	Architecture	Codex CLI

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-5.6 Sol

Latest frontier agentic coding model — the new Codex default.

GPT-5.6 Sol is OpenAI's newest frontier model for agentic coding: the default engine of modern Codex, tuned for long autonomous sessions, repo-scale edits and reliable tool calling. Pick it when you want the strongest coder in the GPT line.

More about GPT-5.6 Sol →

Quick take: pick GPT-5.6 Sol when cost matters most; pick Claude Opus 4.8 when you need the largest context. With AnyModel you don't have to choose up front — switch the model id any time.

FAQ

Which is cheaper, Claude Opus 4.8 or GPT-5.6 Sol?

GPT-5.6 Sol is cheaper on output tokens ($0.1 vs $0.2 per 1M).

Which has a larger context window, Claude Opus 4.8 or GPT-5.6 Sol?

Claude Opus 4.8 has the larger context window (1M).