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Claude Opus 5.5
● live- Released
- September 22, 2026
- Price
- $4 / $20 per 1M tokens
- Context
- 1M tokens
- Bench index
- 98.1 · #1 of 45
The watchers keep tracking it: lineup changes, pricing moves and deprecations all alert.
Launch details
Live — Sep 22; $4/$20 per MTok, down from Opus 5 at $5/$25; 1M ctx / 128K out; adaptive thinking always on, default effort medium; cache reads 5% of base input; Anthropic now says start here for most workloads, and Opus 5 is legacy; fast mode (speed: 'fast', up to 2.5x the output tokens per second by Anthropic's figure) at $8 / $40 per MTok, double standard, left research preview Oct 15 with no waitlist, access request or beta header; on the Claude API and on Claude in Microsoft Foundry (Azure-hosted), not on Bedrock, Google Cloud, Claude Platform on AWS, the Batch API or Priority Tier; @ClaudeDevs says Google Cloud is coming soon (Anthropic's fast mode docs, read Oct 16).Answering in 0.5s· answered Is Claude down? →
Watch for Anthropic’s next model, free →Launch report (PDF)
Timeline
SemiAnalysis released GDPx on November 2, a new agentic benchmark of 206 tasks across 11 domains, and the best model it tested scores 12%. Claude Opus 5.5 leads at 12.0, Gemini 4 Carbon is second at 10.9 and GPT-6 Astra third at 9.6. We read the leaderboard directly at gdpx.semianalysis.com.
Anthropic's models now run about 3.6 times as many tokens a day on OpenRouter as they did before Claude Opus 5.5 launched, according to OpenRouter's own usage data.
Anthropic opened a research preview of Claude Duet on October 21, a new app in which Claude works as a proactive agent: it brings you what needs your attention, completes tasks you hand it, keeps working when you step away, and checks with you before it acts on your behalf.
Anthropic took fast mode for Claude Opus 5.5 out of research preview on October 15 and removed the waitlist. Any Claude API user can now set speed: "fast" on an Opus 5.5 request with no access request and no beta header; requests that still send the old header keep working.
UPDATE, OCTOBER 15: Anthropic took Opus 5.5 fast mode out of research preview and removed the waitlist, so the access catch below no longer applies to Opus 5.5. It is now on Claude in Microsoft Foundry too, at the same $8 / $40. Fast mode on Opus 5 and Opus 4.8 is still a research preview.
Claude Opus 5.5 is live. Our sweep read the id claude-opus-5-5 at 16:24:44 UTC on September 22 and the alert went out at 16:25:45 - 61 seconds later, to 307 inboxes and one phone. The hunt that caught it was armed the previous day, before the model had a confirmed name, on the version range rather than on the rumour.
Polymarket's "Next Claude Opus released by...?" book, read directly at 06:49 UTC, September 21: 83% by September 24, 91% by September 27, 95% by September 30. Polymarket's own post about nine hours earlier had Thursday at 72%, so the number has been climbing through the day.
On the bench index
Coding leaderboard
#1 of 45 on the coding index, at 96 · combines LMArena · Coding, LiveBench · Coding, Vals Vibe Code Bench
The official word
We alert on verified API behavior, never on announcements alone — but when Anthropic speaks, it's here: anthropic.com/news ↗
Where to use Claude Opus 5.5
37 providers list Claude Opus 5.5 in the models.dev catalog (as of 2026-11-05), under the model ids shown below.
claude-opus-5-5anthropic.claude-opus-5-5 · au.anthropic.claude-opus-5-5 · eu.anthropic.claude-opus-5-5claude-opus-5-5@defaultclaude-opus-5-5@defaultclaude-opus-5-5claude-opus-5-5anthropic/claude-opus-5.5anthropic/claude-opus-5.5 · anthropic/claude-opus-5.5-fastclaude-opus-5-5anthropic/claude-opus-5.5claude-opus-5-5anthropic/claude-opus-5-5Also listed by Boundless, Cloudflare AI Gateway, CommandCode, Cortecs, CrossModel, DevPass (LLM Gateway), DigitalOcean, Eden AI, GitHub Copilot, GitLab Duo, Kilo Gateway, LLM Gateway, Merge Gateway, NanoGPT, NEAR AI Cloud, Neon, Ofox, OpenCode, Perplexity Agent, Prime Inference, Requesty, Standard Compute, Venice AI, Vivgrid, ZenMux.
Listings cover the model family, so a provider may list a sibling tier under the same name. Check the id before you build on it.
Try it first-hand on Anthropic's own Claude Console playground ↗
Claude Opus 5.5: quick answers
Is Claude Opus 5.5 out?
Yes. Claude Opus 5.5 is live and has been since September 22, 2026.
When was Claude Opus 5.5 released?
September 22, 2026.
Is Claude Opus 5.5 good for coding?
On the ArtificialWatch coding index it scores 96, #1 of 45 ranked models. The index combines LMArena · Coding, LiveBench · Coding and Vals Vibe Code Bench, taking the median of each model's percentile across them.
Who makes Claude Opus 5.5?
Anthropic. ArtificialWatch also tracks Claude Haiku 5.5, Claude Sonnet 5.5, Fable 5.1, Mythos 5.1, Claude Opus 5, Fable 5, Claude Sonnet 5 and Mythos 5 from Anthropic.
Where can I use Claude Opus 5.5?
37 providers list it in the models.dev catalog, including Anthropic, Amazon Bedrock, Vertex, Vertex (Anthropic) and Azure. The exact model ids each one lists are on this page.
How much does Claude Opus 5.5 cost?
Anthropic's own API lists Claude Opus 5.5 (claude-opus-5-5) at $4 per million input tokens and $20 per million output tokens, and $0.20 per million cached input tokens. Prices as published in the models.dev catalog, as of 2026-11-05.
What is Claude Opus 5.5's context window?
1M tokens, with up to 128K output tokens per response, as Anthropic lists Claude Opus 5.5 (claude-opus-5-5).
Every live model's API price, side by side → · What a workload costs on Anthropic models →
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