Anthropic releases Claude Opus 5
Near-Fable-5 intelligence at half the price
Confirmed
Importance: major (4 of 5)The takeaway
Claude Opus 5 (claude-opus-5) launched on July 24, 2026 at $5/$25 per million tokens.
Status
- Claim
Confirmed
- Our reporting
- High confidence
- Importance
- Major (4 of 5)
- Last verified
- 29 October 2026
Your AI and this story
- GPT-6 Astra85 days after its cutoff
- Claude Opus 5.524 days after its cutoff
- Gemini 4 Hydrogen115 days after its cutoff
- Grok 4.754 days after its cutoff
None of these four assistants can know about it. The closest, Claude Opus 5.5, stops 24 days before it.
Key facts
- Released July 24, 2026; model id claude-opus-5; $5 input / $25 output per 1M tokens; fast mode 2x base price for ~2.5x speed
- Context 1M tokens (default and max), 128K output; thinking on by default
- Frontier-Bench v0.1: more than doubles Opus 4.8’s performance; CursorBench 3.2 within 0.5% of Fable 5 at half the cost (Anthropic)
- Anthropic reports an ARC-AGI-3 score 3x higher than the next-best model (exact number not captured)
- Default model on Claude Max; cybersecurity classifiers intervene 85% less often than on Fable 5
- Anthropic called it its ‘most aligned model to date’ on the behavioral audit
- Irregular (July 24): on a nine-challenge CyScenarioBench subset with deployment mitigations disabled, Opus 5 averaged a 33.7% solve rate vs Opus 4.8 24.4%, Sonnet 5 3.3% and Claude Mythos 5 47.0%; most attempts did not reach the scenario objective
What happened
Opus 5 upgrades Opus 4.8 with gains in agentic coding, computer use and long-horizon knowledge work. It is much better at verifying its own work and iterating until it succeeds. New API betas arrived with it: changing tools mid-conversation and automatic fallback to alternative models. It remained behind Mythos 5 on cyber exploitation and biology research.
Reception was mixed. Commentators such as MindStudio reported developer complaints that it was verbose, turned small fixes into large rewrites, and flagged trivial issues as urgent.
Why it matters
Opus 5 brought most of Fable 5’s capability to half the price. Its reception problems explain why Opus 5.5’s launch messaging stressed clear, concise communication.
Sources
9 sources from 9 sites. Numbers match the chips in the text.
9 sources: 4 primary, 3 press, 2 reactions
Primary
- Introducing Claude Opus 5 (Anthropic)anthropic.com, official
- Claude Opus 5 System Card (PDF)www-cdn.anthropic.com, paper
- Claude Opus 5 docs overviewplatform.claude.com, docs
- Irregular: Assessing Claude Opus 5 against offensive security benchmarks (July 24)irregular.com, official
Press
- TechCrunch: Anthropic launches Opus 5techcrunch.com, press
- Axios: Anthropic releases new model, Opus 5axios.com, press
- 9to5Mac: Anthropic upgrades Claude with Opus 59to5mac.com, press
Reactions
- Simon Willison: Introducing Claude Opus 5simonwillison.net, discussion
- MindStudio: Why is Opus 5 getting bad reviews despite top benchmarks?mindstudio.ai, discussion
Changes
- Added Irregular’s CyScenarioBench result (read directly) (news agent)
- Filed
