Claude Fable 5
Anthropic's most capable general model on its own benchmarks, priced accordingly, and worth it only when the task genuinely warrants it.
The facts at a glance
Pricing last checked August 7, 2026. Prices change and vary by region. Check the official pricing page ↗
Assessment
What it does well
- Anthropic reports state of the art on nearly all tested benchmarks, with the largest margins on long horizon tasks
- Reported top scores on Cognition's FrontierCode and Hebbia's Finance Benchmark
- Adaptive thinking is always on rather than being a mode you have to remember to enable
Where it falls short
- Ten times the input price of Claude Sonnet 5
- Safeguards silently fall back to Claude Opus 4.8 for cybersecurity exploitation, biological and chemical weapons, and distillation shaped requests, which Anthropic says triggers in under 5 percent of sessions
- It was withdrawn after announcement and redeployed three weeks later, which is worth knowing if you are planning a dependency on it
Privacy and data control
Commercial and API terms apply. Anthropic published a further biology safeguards update dated 7 August 2026 that may affect specific research use cases.
The longer read
The silent fallback
Anthropic documents that Fable 5 falls back to Claude Opus 4.8 for a narrow set of request shapes, including cybersecurity exploitation and bio and chemical weapons topics. It says this triggers in under 5 percent of sessions on average. If you are benchmarking Fable 5 on security research, you may not always be measuring Fable 5.
How it performs by outcome
We assess products against a job, not a leaderboard. These are the outcomes this entry is compared under.
Worth comparing against
How this profile was produced
Source review. Every fact here is drawn from the provider documentation linked below and checked on the date shown. We have not yet run this entry through a controlled test, and no scoring is implied.
Read the full review methodology →