Claude Sonnet 5.5 Is Now Available

Anthropic released Claude Sonnet 5.5 yesterday. It is now the default Anthropic model in AI Data Stream — the best balance of speed, capability and cost for everyday analytics work. Sonnet 5 remains available as the previous generation, so you can compare the two on your own data before switching.

Pricing

Sonnet 5.5 costs exactly what Sonnet 5 did on the standard API we use:

• Input: $2 per million tokens
• Output: $10 per million tokens
• Cache reads: $0.20 per million tokens
• Cache writes: $2.50 per million tokens

The per-token price is unchanged, but Anthropic says Sonnet 5.5 completes typical tasks with fewer tokens, putting the saving at up to 30% per task compared with Sonnet 5. In AI Data Stream that shows up on multi-step questions: fewer wasted tool calls means a cheaper conversation even though each token costs the same.

What’s New

The headline is speed. Sonnet 5.5 generates output more than 30% faster than Sonnet 5, so long reports and multi-connection comparisons come back noticeably sooner. The capability jump is larger than a point release suggests: on GDPval-AA, Artificial Analysis’s benchmark of real professional work across 44 occupations, Sonnet 5.5 scores 1844 Elo against 1449 for Sonnet 5 — two points behind Opus 5.5’s 1846, at half the price. On CursorBench, Cursor’s benchmark built from real coding sessions, it scores 55.5% against 34.1% for Sonnet 5. For our users the practical difference is in follow-through: when you ask it to pull data from several connections and reconcile them, it gets there more reliably and with fewer detours. See Anthropic’s announcement for the full details.

Anthropic has also said that Claude Haiku 5.5 will follow in the coming weeks. We will add it to the picker when it ships.

Sonnet 4.6 Has Been Retired

We have removed Sonnet 4.6 from the model picker. If it was your default, you will move to Sonnet 5.5 automatically the next time you start a conversation — no action needed. Sonnet 5 is still available if you prefer to stay on the previous generation.

Effort Levels

Sonnet 5.5 supports the full effort scale: Low, Medium, High, Extra High, Max. Anthropic’s default for it is High, the same as Sonnet 5, and the picker still starts on the effort you saved for your Anthropic provider, so nothing changes unless you change it. The levels have been recalibrated, though: Medium on Sonnet 5.5 does more work than Medium on Sonnet 5, so it is worth trying a step below your usual setting on a familiar question and comparing. Sonnet 4.6 was the last Claude model without Extra High, so every Claude model in the picker except Haiku now offers all five levels.

The Full Claude Lineup

• Claude Fable 5.1 — Most powerful, premium; for the hardest reasoning
• Claude Fable 5 — Previous-generation Fable
• Claude Opus 5.5 — Most capable at standard pricing, for demanding tasks
• Claude Opus 5 — Previous-generation Opus
• Claude Sonnet 5.5 — Best balance of speed and capability (default)
• Claude Sonnet 5 — Previous generation
• Claude Haiku 4.5 — Fastest, great for quick queries

Switching Models

1. Go to Settings > AI Providers
2. Click your Anthropic provider
3. Select your preferred model from the dropdown
4. Save

Or select it from the model picker when starting a new conversation.

Questions?

If you have any questions, contact us or check our AI providers documentation.