Claude Fable 5.1 vs Claude Haiku 5.5.
Verdict by category, tale of the tape, shared benchmarks only, and cost at three workloads — all from the tracked data.
Verdict by category
| Category | Claude Fable 5.1 | Claude Haiku 5.5 | Winner |
|---|---|---|---|
| League Score | 97.3 | 66.2 | Claude Fable 5.1 |
| Coding (SWE-bench %) | — | — | — |
| Reasoning (GPQA %) | 93.7 | — | — |
| Context (tokens) | 1000000 | 1000000 | Draw |
| Speed (tok/s) | — | — | — |
| Price (blended $/1M) | $20.00 | $0.20 | Claude Haiku 5.5 (cheaper) |
Tale of the tape
| Spec | Claude Fable 5.1 | Claude Haiku 5.5 |
|---|---|---|
| Maker | Anthropic | Anthropic |
| Released | Sep 1, 2026 | Oct 7, 2026 |
| League Score | 97 | 66 |
| Context | 1,000,000 tokens | 1,000,000 tokens |
| Max output | 128,000 | 128,000 |
| $/1M input | $10.00 | $0.10 |
| $/1M output | $50.00 | $0.50 |
| Weights | Closed | Closed |
| Speed | — | — |
Head-to-head benchmarks (shared only)
| Benchmark | Claude Fable 5.1 | Claude Haiku 5.5 |
|---|---|---|
| LiveBench overall | 85.7 | 69.8 |
Cost at three workloads
| Workload | Claude Fable 5.1 | Claude Haiku 5.5 |
|---|---|---|
| Light — 1M in / 250K out | $22.50 | $0.23 |
| Standard — 10M in / 2.5M out | $225.00 | $2.25 |
| Long-context — 50M in / 5M out | $750.00 | $7.50 |
The pick
Pick Claude Fable 5.1 if you want the higher overall League Score.
Pick Claude Haiku 5.5 if you want the lower running cost.
All figures from the model database — sources and dates on each model page. Cost your own workload or compare a different pair.
Frequently asked questions
Which is better overall, Claude Fable 5.1 or Claude Haiku 5.5?
Claude Fable 5.1 leads on overall League Score, 97 to 66 — a gap of 31 points on a composite of sourced benchmarks. That is overall form, not every category: check the per-category verdicts before choosing.
Which is cheaper, Claude Fable 5.1 or Claude Haiku 5.5?
Claude Haiku 5.5 is cheaper: $0.20 vs $20.00 blended per 1M tokens (3:1 input/output mix) — about 100.0x less per token.
Which has the bigger context window, Claude Fable 5.1 or Claude Haiku 5.5?
Neither — both take 1M of context.
Are Claude Fable 5.1 and Claude Haiku 5.5 open source?
Claude Fable 5.1 is closed weights — API access only; Claude Haiku 5.5 is closed weights — API access only.