Claude Opus 5.5: release date and what it's for
Released , according to Anthropic's announcement. Anthropic's new default: its docs now say start here for most workloads, and move up to Fable 5.1 only when Opus 5.5 at higher effort still falls short.
- Status
- Live
- Released
- Lab
- Anthropic
- Input
- $4per million tokens
- Output
- $20per million tokens
- Context window
- 1Mtokens
- Max output
- 128Ktokens
API model ID: claude-opus-5-5
Explained: Claude models explained: Opus 5.5, Fable 5.1, Mythos and why there's no Opus 5.1
What is Claude Opus 5.5 capable of?
36 posts from people showing what they made with Claude Opus 5.5, newest and most-reacted first. People are posting agent, 3d, code and science made with it.
Each card is the original post, shown the way X or Reddit embeds it, with a link to where it came from. We picked the ones that show something being made and skipped the benchmark screenshots. We can't vouch for any of them being unedited.
What we've written about Claude Opus 5.5
Thinking Machines launches Inkling 2 Small but holds back its open weights for safety tests
Midway through training, the model got around a network block through an outside service, and the lab stopped the run.
Moonshot releases Kimi K3.1 Pro's weights, but big model hosts must sign a separate deal
Its license lets most companies run it free, but the biggest model hosts have to sign a separate deal with Moonshot first.
Moonshot's Kimi K3.1 Pro lands just behind Claude Opus 5.5, with open weights due November 4
Moonshot stripped cyber training data from the open release, and says that cost it nearly ten points on its own exploit test.
Anthropic opens Claude Duet, an agent that messages you first and asks before it pays
It won't trade securities or move money between accounts, even if you tell it to.
Anthropic says new defenses cut the data distillers take from Claude by 90 to 99%
The company names Zhipu and Moonshot, and says honest developers are paying part of the cost.
Meta releases Muse Wonder, the models Zuckerberg says bring it to the frontier
Meta built them to remember you between chats and push through hard tasks, but its full safety report isn't out yet.
Arena's new Alignment Index ranks GPT-6.1 Sol first and Claude Opus 5.5 second
The new index counts how often agents act without permission, or say they finished a job they didn't.
Chinese AI labs published safety results for 3.6% of 857 models, SemiAnalysis finds
Only one of the nine developers, Zhipu, has published a safety result every year since 2022.
How Claude Opus 5.5 compares on price and context
inputoutput
- Claude Mythos 5.1$10 / $50
- Claude Fable 5.1$10 / $50
- GPT-6 Astra$10 / $50
- Claude Opus 5$5 / $25
- Claude Opus 5.5$4 / $20
- Muse Spark 1.3$1.25 / $4.25
- Gemini 3.8 Flash$0.75 / $3.75
how much it reads at once
- GPT-6 Astra1.05M
- Muse Spark 1.31.05M
- Gemini 3.8 Flash1.05M
- Claude Opus 5.51M
- Claude Mythos 5.11M
- Claude Fable 5.11M
- Claude Opus 51M
Next to the newest Anthropic models and the current model from other labs. Prices are in US dollars per million tokens.
What is Claude Opus 5.5?
Claude Opus 5.5 is a model from Anthropic, built in the US. It's out, and you can use it today.
When did Claude Opus 5.5 come out?
Anthropic released it on September 22, 2026. That date comes from Anthropic's announcement.
More from Anthropic
Claude Mythos 5.1
- in /1M
- $10
- out /1M
- $50
- context
- 1M
Claude Fable 5.1
- in /1M
- $10
- out /1M
- $50
- context
- 1M
Claude Opus 5
- in /1M
- $5
- out /1M
- $25
- context
- 1M
Claude Sonnet 5
- in /1M
- $2
- out /1M
- $10
- context
- 1M
Claude Fable 5
- in /1M
- $10
- out /1M
- $50
- context
- 1M
Claude Haiku 4.5
- in /1M
- $1
- out /1M
- $5
- context
- 200K
Claude Sonnet 4.5
- in /1M
- $3
- out /1M
- $15
- context
- 200K
More news: Anthropic news and Claude updates
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