NewsAnthropic2 min read
Claude Opus 5.5 and Sonnet 5.5: Faster and Cheaper
Anthropic refreshes its mid and top tiers: Opus 5.5 performs close to Fable 5.1 for less money, and Sonnet 5.5 is 30% faster than Sonnet 5.
Key points
- Opus 5.5 (22 September) performs at Fable 5.1 level on most work, at $4 / $20 per million tokens.
- Anthropic says it costs 40% less than Opus 5 on typical work and writes over 30% faster.
- Sonnet 5.5 (28 September) keeps Sonnet 5's $2 / $10 price and is 30% faster.
- Haiku 4.5 remains the budget model; Anthropic has not announced its retirement and gives 60 days' notice.
In one week Anthropic refreshed two of its four models. Claude Opus 5.5 shipped on 22 September and Claude Sonnet 5.5 on the 28th. Both follow the same line: better than the previous version, faster and cheaper per task.
Opus 5.5: nearly Fable, for less than half
Until now, getting Anthropic’s best meant paying for Claude Fable 5.1, at $10 per million input tokens and $50 output. Anthropic says Opus 5.5 performs at Fable 5.1’s level on most work and costs $4 and $20. It is now the model the company recommends as the starting point for nearly everything.
Compared with Opus 5, which is still available, Anthropic says it:
- costs 40% less on typical work, partly because it needs fewer tokens to reach the same answer;
- generates text over 30% faster;
- improves at agentic coding, knowledge work and computer use.
A technical note for developers: on Opus 5.5 adaptive thinking is always on and the default effort is medium. If you are moving from Opus 5, read the official migration guide.
Sonnet 5.5: the balanced option, faster
Sonnet is the everyday tier: good quality at a moderate price. Sonnet 5.5 keeps Sonnet 5’s $2 and $10 price, and Anthropic says it is 30% faster and up to 30% cheaper per task. It is already the model you chat with on Claude.ai, on web, iOS and Android.
The Claude family today
| Model | Best for | Price (input / output) |
|---|---|---|
| Fable 5.1 | The hardest reasoning and very long agent runs | $10 / $50 |
| Opus 5.5 | The recommended choice for most work | $4 / $20 |
| Sonnet 5.5 | Speed with good quality | $2 / $10 |
| Haiku 4.5 | Fastest and cheapest | $1 / $5 |
Watch Haiku 4.5: Anthropic only commits to keeping it until 15 October 2026. It has not announced a retirement and gives at least 60 days’ notice, but if you use it in production, look out for a successor. Our AI model guide explains how each family fits next to OpenAI, Google and the rest.
What was said on X
The official announcements, as they were posted. Tap to open them on X.
