Yesterday, Anthropic introduced a thoughtful and proactive model, Claude Opus 5, that comes close to the frontier intelligence of Fable 5 at half the price.
Claude Opus 5
On coding and knowledge work evaluations like Frontier-Bench and GDPval-AA, Opus 5 is the new state-of-the-art, though it remains behind Mythos 5 on cybersecurity tasks.
Claude Opus 5 provides greatly improved performance for the same cost as its predecessor, Opus 4.8. This latest model excels on valuable software engineering tasks, knowledge work and problem-solving tasks on Frontier-Bench v0.1, CursorBench 3.2, ARC-AGI 3, Zapier AutomationBench and OSWorld 2.0.
It shows better performance than Opus 4.8 on every life science evaluation, which covers topics including structural biology, organic chemistry, and bioinformatics. The model is also capable of producing much stronger visual outputs. During evaluation and early testing, it was found that the model is much stronger at verifying its work and iterating carefully until it succeeds.
During pre-deployment testing, the company’s automated behavioural audit found Opus 5 to be its most aligned model to date. It’s also the safest model yet in terms of avoiding reckless actions that could have hard-to-reverse side effects. Opus 5 remains behind Mythos 5 in both biology research and offensive cybersecurity. Though it comes close to Mythos 5 at finding cybersecurity vulnerabilities, it can’t exploit them.
The safeguards applied for Opus 5 are similar to Opus 4.8, except for some stronger guardrails on a narrow range of cyber tasks. Opus 5’s cyber classifiers are expected to intervene around 85% less often than they do for Fable 5. In Claude.ai, Claude Code, and Claude Cowork, any flagged requests will fall back to Opus 4.8 by default.
Availability
Opus 5 is available on all platforms, priced at $5 per million input tokens and $25 per million output tokens. Developers can get started with claude-opus-5 on the Claude API.
It’s also offered in Fast Mode, where it runs around 2.5 times the default speed. Claude Opus 5 is the new default model on Claude Max, and the strongest model on Claude Pro
