Claude Fable 5.1 vs Claude Opus 5
Side-by-side comparison of API pricing, specs, benchmarks, and capabilities
| Specification |
by Anthropic
|
by Anthropic
|
|---|---|---|
| Overview | ||
| Status | Current flagship | Current flagship |
| Released | Sep 1, 2026 | Jul 24, 2026 |
| Pricing per million tokens | ||
| Input | $10.00/Mtok | $5.00/Mtok |
| Output | $50.00/Mtok | $25.00/Mtok |
| Blended avg | $20.00/Mtok | $10.00/Mtok |
| Cached input | $0.250/Mtok | $0.500/Mtok |
| Price basis | Cache hits and refreshes on Claude Fable 5.1 (and Claude Mythos 5.1) are priced at 0.025x the base input price — $0.25 per 1M tokens — where every other Claude model uses the standard 0.1x multiplier. Base $10/$50 per 1M tokens; Batch API $5/$25. Verified 2026-09-01 against platform.claude.com/docs/en/about-claude/pricing. | — |
| Specifications | ||
| Context window | 1M tokens | 1M tokens |
| Parameters | Proprietary | Proprietary |
| Speed (TPS) | — | — |
| Modalities | ||
| Input |
textimage
|
textimage
|
| Benchmarks source: Vellum LLM Leaderboard | ||
| Avg benchmark score | 54.2 | 84.2 |
| Perf / dollar | 2.7 | 8.4 |
| Humanity's Last Exam | 65 | 64.7 |
| AutoBench | 31.4 | 26 |
| SWE-Bench Verified | — | 97 |
| Terminal-Bench 2.1 | 55.8 | — |
| BrowseComp | — | 90.8 |
| OSWorld-Verified | 41.7 | — |
| Independent composite scores each on its own scale — not part of the average above | ||
| AA Intelligence Index | 65.7 | 63.1 |
| AA Agentic Index | 61.3 | 59.2 |
| AA-Omniscience Index (−100–100) | 43.5 | 37.1 |
| GDPval-AA v2 | 1853 ELO | 1823.9 ELO |
| Providers | ||
| Available from |
Anthropic — $10.00/$50.00/Mtok
|
Anthropic — $5.00/$25.00/Mtok
|
Cost at scale
1M tokens · 50/50 input/output| Volume | Claude Fable 5.1 | Claude Opus 5 | Savings |
|---|---|---|---|
| 1M tokens | $20 | $10 | $10 (50%) |
| 10M tokens | $200 | $100 | $100 (50%) |
| 100M tokens | $2000 | $1000 | $1000 (50%) |
| 1000M tokens | $20000 | $10000 | $10000 (50%) |
When to pick which
distilled from the pricing and spec data above- your workload re-reads context (agents, RAG, long chats): cached input costs $0.250/Mtok — 98% off its list input price
- cost dominates: $10.00/Mtok blended vs $20.00 — 50% less on the same 50/50 token mix
- raw capability matters more than price: 84.2 vs 54.2 average benchmark score
The cheaper option here — Claude Opus 5 costs $10.00/Mtok blended on Anthropic.
Summary
Claude Fable 5.1 by Anthropic costs $10.00/Mtok input and $50.00/Mtok output, with a 1M-token context window. It supports text, image input.
Claude Opus 5 by Anthropic costs $5.00/Mtok input and $25.00/Mtok output, with a 1M-token context window. It supports text, image input.
On a blended cost basis, Claude Opus 5 is 50% cheaper than Claude Fable 5.1.
On benchmarks, Claude Opus 5 scores higher (84.2 vs 54.2) on average. In terms of value, Claude Opus 5 has better performance per dollar (8.4 vs 2.7).
Note: Pricing is per million tokens. Actual costs vary with usage patterns, prompt caching, and batch discounts. Always verify against official provider pricing pages.