Claude Haiku 5.5 vs Claude Fable 5.1
Claude Haiku 5.5 and Claude Fable 5.1 are within three points on the Models at Work leaderboard, which we treat as a tie (80 vs 78). Claude Haiku 5.5 is about 100× cheaper per blended million tokens ($0.20 vs $20). On Artificial Analysis' independent Intelligence Index, Claude Fable 5.1 leads 53 to 43.
| Claude Haiku 5.5 · Anthropic | Claude Fable 5.1 · Anthropic | |
|---|---|---|
| Leaderboard rank | #8 | #10 |
| Score (0–100) | 80 | 78 |
| Tier | Fast and cheap | Frontier |
| Price per 1M tokens | $0.10 in · $0.50 out | $10 in · $50 out |
| Context window | 1M | 1M |
| Open weights | No | No |
| Artificial Analysis Intelligence Index | 43 | 53 |
| Arena text score | — | 1501 |
| Humanity's Last Exam, Diamond (Scale) | — | 51.3 |
| Best for | Classification and extraction, Routing tiers, Latency-sensitive paths | Long-horizon agents, Problems Opus fails on, Demanding reasoning |
Choose Claude Haiku 5.5 if…
- you need classification and extraction
- you need routing tiers
- you need latency-sensitive paths
Ten cents a million and, per the people using it, smarter than the other ten-cent model; mind the 100K cliff.
Caveats: Price jumps five-fold above 100K input tokens, which commenters call an absurdly low cutoff for agent runs.
Choose Claude Fable 5.1 if…
- you need long-horizon agents
- you need problems opus fails on
- you need demanding reasoning
The specialist: Anthropic's own docs say to reach for it when Opus 5.5 at high effort still falls short, and the price says the same.
Caveats: Ten dollars per million input is the highest in this table alongside Astra.
What practitioners say
Claude Haiku 5.5: The thread had over a thousand points in a day; the recurring reports are near-perfect structured classification in production and 'noticeably smarter than GPT-6 Luna', against complaints about the 100K pricing tier.
Questions people ask
Which is better, Claude Haiku 5.5 or Claude Fable 5.1?
Claude Haiku 5.5 and Claude Fable 5.1 are within three points on the Models at Work leaderboard, which we treat as a tie (80 vs 78). Claude Haiku 5.5 is about 100× cheaper per blended million tokens ($0.20 vs $20). On Artificial Analysis' independent Intelligence Index, Claude Fable 5.1 leads 53 to 43.
When should I choose Claude Haiku 5.5 over Claude Fable 5.1?
Choose Claude Haiku 5.5 for classification and extraction, routing tiers, latency-sensitive paths. Ten cents a million and, per the people using it, smarter than the other ten-cent model; mind the 100K cliff.
When should I choose Claude Fable 5.1 over Claude Haiku 5.5?
Choose Claude Fable 5.1 for long-horizon agents, problems opus fails on, demanding reasoning. The specialist: Anthropic's own docs say to reach for it when Opus 5.5 at high effort still falls short, and the price says the same.
Which is cheaper, Claude Haiku 5.5 or Claude Fable 5.1?
Claude Haiku 5.5 costs $0.10 per million input tokens and $0.50 per million output tokens on Anthropic's list price (Claude pricing, read Oct 11, 2026). Claude Fable 5.1 costs $10 per million input tokens and $50 per million output tokens on Anthropic's list price (Claude pricing, read Oct 11, 2026).
Scores come from the Models at Work leaderboard: Score is 0 to 100 and computed, not typed: 55% independent evals (Artificial Analysis, Arena, Scale SEAL, Epoch, each scaled against its natural floor and the best score in this table, then averaged), 15% blended price on a fixed log scale ($0.05 per million is 100, $60 is 0), 15% practitioner sentiment from Signals and community threads, 15% operational fit (context window, open weights). A missing component drops out and the rest are reweighted. A model with no independent eval yet is provisional and ranks below every measured one. Within three points is a tie. Vendor-published figures are labelled and never counted. Prices are vendor list prices where published; blended figures assume three input tokens per output token.