Anthropic ships Opus 5.5: up to 40% cheaper than Opus 5, pulling Codex users back to Claude
danshipper · x · 2026-09-23
Anthropic has released Claude Opus 5.5, and early hands-on testing from Every suggests it's a serious contender as a daily driver:
- Pricing: up to 40% cheaper than Opus 5, and it sometimes beats rival Fable 5.1 in testing—pulling recent Codex converts back to Claude.
- Coding: The author now reaches for Opus over Fable on big end-to-end projects; Kieran Klaassen has replaced Fable 5.1 with Opus for daily product work, calling it his new favorite.
- Writing: Produces legible prose (reading ease score of 68.42) but still trails Astra on writing tasks.
- Independent test: nityeshaga spent days testing and judges it better than Fable 5.1, with big gains in writing style, teaching ability, instruction-following over long context, and performance near the context limit. She had it build a multi-page explorable explanation of how the web works in HTML—it worked 4+ hours in a single shot—versus same-task runs on Fable 5.1 and Opus 5.
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