The comparison · July 25, 2026
Opus 5 vs Fable 5: when “nearly as smart, half the price” is enough.
Anthropic's own positioning makes this comparison unusually honest: Fable 5 is smarter, Opus 5 is cheaper and easier to access. The practical question is where the gap actually bites.
| Opus 5 | Fable 5 | |
|---|---|---|
| API price (per 1M in/out) | $5 / $25 | $10 / $50 |
| Claude Pro | Included — strongest model on Pro | Usage credits only (one-time $100 included) |
| Claude Max / Team Premium | Included — the default model | Included up to 50% of weekly limits |
| Capability | "Nearly all" of Fable 5's intelligence (Anthropic-reported) | The top of Anthropic's published line |
| Safety classifiers | ~85% fewer interventions (Anthropic-reported) | Strictest tier; 30-day retention policy applies |
| Data retention | Exempt from the 30-day policy | 30-day retention policy |
The honest decision rules
Default to Opus 5 if you're on Pro (it's the best you get without credits), you run high-volume agentic work on the API (half rate compounds fast), or your work keeps tripping Fable 5's stricter classifiers.
Stay with Fable 5 if you're on Max (it's already included up to the 50% cap — use it for planning, judging, and the genuinely hard steps) or your task provably needs the extra capability — the classic pattern is Fable 5 plans and reviews while a cheaper model executes.
Both at once is the real answer for most serious setups: flagship judgment where it matters, cheap tokens for volume. That split-stack arithmetic — with real dollar numbers per workflow — is what the Field Guide does weekly; read a full free issue to see the format.
Independent benchmark rounds for Opus 5 were still landing at the time of writing; we'll update this page as third-party numbers (not just Anthropic's) come in. Leave your email below to get that update.
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