Fable 5 vs Opus 4.8: Mythos-Class vs the GA Flagship
| Spec | Claude Fable 5 | Claude Opus 4.8 |
|---|---|---|
| Tier | Mythos-class (above Opus) | Opus |
| Availability (general) | Suspended (export-control directive) ↗ | Available |
| Released | June 9, 2026 ↗ | — |
| Context window | 1M tokens | 1M tokens unofficial |
| Max output | Up to 128k tokens | Up to 64k tokens unofficial |
| Input price (per M tokens) | $10 / M (after intro window) | $5 / M |
| Output price (per M tokens) | $50 / M (after intro window) | $25 / M |
| Data retention | 30 days | — |
| Zero-data-retention (ZDR) | No ZDR | — |
| Covered Model | Yes — Covered Model | — |
| Safeguards | Classifiers for cyber, bio/chem, distillation; reroute to Opus 4.8 | — |
| How to access | Claude API, AWS Bedrock, Google Cloud, Microsoft Foundry (when not suspended) | Claude API, apps, cloud marketplaces |
Tier and price
Fable 5 is part of the Mythos-class, which sits above Opus in Anthropic's lineup. It carries a 1M-token context, up to 128k output, and $10/$50 per-million pricing after its intro period. Opus 4.8, the current GA flagship, runs at $5/$25 per million — meaningfully cheaper on both input and output.
Availability is the deciding factor
The capability gap matters less than reachability right now. Fable 5 access is suspended under the June 12, 2026 US export-control directive, while Opus 4.8 is available across the API and major clouds. If you need to build today, Opus 4.8 is the answer by default.
When Fable 5 wins
Once access is restored, Fable 5 is the better pick for the most demanding frontier work — very long-context reasoning, large synthesis tasks, and cases where Opus 4.8 leaves capability on the table. Note that Fable 5 also wraps classifiers that can reroute flagged sessions to Opus 4.8 anyway, so for sensitive domains the two can converge in practice.
Caveat
Treat any head-to-head benchmark figures as unofficial until Anthropic's system card lands. Pick on price, context needs, and current availability.
Frequently asked questions
Is Fable 5 better than Opus 4.8?
On raw capability it is a tier higher, but it costs more and is currently suspended. For most live work Opus 4.8 is the more practical flagship.
Why is Fable 5 more expensive?
Fable 5 is Mythos-class, above Opus, with a larger context window. Its $10/$50 pricing reflects that tier; Opus 4.8 is $5/$25.
Can I use Fable 5 right now?
Not broadly. Access is suspended under an export-control directive. Check the live status page and use Opus 4.8 in the meantime.
Sources & further reading
- Anthropic pricingOfficialanthropic.com
- Anthropic — Fable & Mythos access noticeOfficialanthropic.com
Facts on this page link to their source. Quotes are kept under 15 words and attributed; figures labelled unofficial are third-party until Anthropic publishes system-card numbers.