Fable vs Opus vs Sonnet vs Haiku: Claude models head-to-head

Compare two Claude models

Fable

Opus

Sonnet

Haiku

Fable 5.1vsOpus 5.5

Opus 5.5 at Medium gives the same quality as Fable 5.1 at Max for 8.3× less per task.

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Effort	Fable 5.1		Opus 5.5
Effort	cost	score	cost	score
low	70×	64.8 %	25×	66.0 %
medium	84×	67.2 %	35×	70.8 %
high	102×	68.2 %	43×	72.2 %
xHigh	186×	69.8 %	74×	73.9 %
max	293×	70.6 %	194×	74.7 %

Effort	Fable 5.1	Fable 5
low	70×	64.8 %	69×	60.5 %
medium	84×	67.2 %	95×	64.0 %
high	102×	68.2 %	115×	65.9 %
xHigh	186×	69.8 %	165×	66.9 %
max	293×	70.6 %	270×	67.8 %

Effort	Fable 5.1	Opus 5.5
low	70×	64.8 %	25×	66.0 %
medium	84×	67.2 %	35×	70.8 %
high	102×	68.2 %	43×	72.2 %
xHigh	186×	69.8 %	74×	73.9 %
max	293×	70.6 %	194×	74.7 %

Effort	Fable 5.1	Opus 5
low	70×	64.8 %	39×	62.5 %
medium	84×	67.2 %	57×	66.1 %
high	102×	68.2 %	84×	68.0 %
xHigh	186×	69.8 %	111×	69.2 %
max	293×	70.6 %	148×	69.6 %

Effort	Fable 5.1	Sonnet 5.5
low	70×	64.8 %	12×	58.5 %
medium	84×	67.2 %	13×	61.7 %
high	102×	68.2 %	18×	66.9 %
xHigh	186×	69.8 %	33×	70.9 %
max	293×	70.6 %	115×	72.8 %

Effort	Fable 5.1	Sonnet 5
low	70×	64.8 %	16×	48.3 %
medium	84×	67.2 %	23×	52.8 %
high	102×	68.2 %	33×	55.9 %
xHigh	186×	69.8 %	50×	57.5 %
max	293×	70.6 %	109×	60.1 %

Effort	Fable 5.1	Haiku 5.5
low	70×	64.8 %	1.0×	51.0 %
medium	84×	67.2 %	1.4×	55.5 %
high	102×	68.2 %	2.2×	58.6 %
xHigh	186×	69.8 %	4.3×	61.8 %
max	293×	70.6 %	12×	64.2 %

Effort	Fable 5	Opus 5.5
low	69×	60.5 %	25×	66.0 %
medium	95×	64.0 %	35×	70.8 %
high	115×	65.9 %	43×	72.2 %
xHigh	165×	66.9 %	74×	73.9 %
max	270×	67.8 %	194×	74.7 %

Effort	Fable 5	Opus 5
low	69×	60.5 %	39×	62.5 %
medium	95×	64.0 %	57×	66.1 %
high	115×	65.9 %	84×	68.0 %
xHigh	165×	66.9 %	111×	69.2 %
max	270×	67.8 %	148×	69.6 %

Effort	Fable 5	Sonnet 5.5
low	69×	60.5 %	12×	58.5 %
medium	95×	64.0 %	13×	61.7 %
high	115×	65.9 %	18×	66.9 %
xHigh	165×	66.9 %	33×	70.9 %
max	270×	67.8 %	115×	72.8 %

Effort	Fable 5	Sonnet 5
low	69×	60.5 %	16×	48.3 %
medium	95×	64.0 %	23×	52.8 %
high	115×	65.9 %	33×	55.9 %
xHigh	165×	66.9 %	50×	57.5 %
max	270×	67.8 %	109×	60.1 %

Effort	Fable 5	Haiku 5.5
low	69×	60.5 %	1.0×	51.0 %
medium	95×	64.0 %	1.4×	55.5 %
high	115×	65.9 %	2.2×	58.6 %
xHigh	165×	66.9 %	4.3×	61.8 %
max	270×	67.8 %	12×	64.2 %

Effort	Opus 5.5	Opus 5
low	25×	66.0 %	39×	62.5 %
medium	35×	70.8 %	57×	66.1 %
high	43×	72.2 %	84×	68.0 %
xHigh	74×	73.9 %	111×	69.2 %
max	194×	74.7 %	148×	69.6 %

Effort	Opus 5.5	Sonnet 5.5
low	25×	66.0 %	12×	58.5 %
medium	35×	70.8 %	13×	61.7 %
high	43×	72.2 %	18×	66.9 %
xHigh	74×	73.9 %	33×	70.9 %
max	194×	74.7 %	115×	72.8 %

Effort	Opus 5.5	Sonnet 5
low	25×	66.0 %	16×	48.3 %
medium	35×	70.8 %	23×	52.8 %
high	43×	72.2 %	33×	55.9 %
xHigh	74×	73.9 %	50×	57.5 %
max	194×	74.7 %	109×	60.1 %

Effort	Opus 5.5	Haiku 5.5
low	25×	66.0 %	1.0×	51.0 %
medium	35×	70.8 %	1.4×	55.5 %
high	43×	72.2 %	2.2×	58.6 %
xHigh	74×	73.9 %	4.3×	61.8 %
max	194×	74.7 %	12×	64.2 %

Effort	Opus 5	Sonnet 5.5
low	39×	62.5 %	12×	58.5 %
medium	57×	66.1 %	13×	61.7 %
high	84×	68.0 %	18×	66.9 %
xHigh	111×	69.2 %	33×	70.9 %
max	148×	69.6 %	115×	72.8 %

Effort	Opus 5	Sonnet 5
low	39×	62.5 %	16×	48.3 %
medium	57×	66.1 %	23×	52.8 %
high	84×	68.0 %	33×	55.9 %
xHigh	111×	69.2 %	50×	57.5 %
max	148×	69.6 %	109×	60.1 %

Effort	Opus 5	Haiku 5.5
low	39×	62.5 %	1.0×	51.0 %
medium	57×	66.1 %	1.4×	55.5 %
high	84×	68.0 %	2.2×	58.6 %
xHigh	111×	69.2 %	4.3×	61.8 %
max	148×	69.6 %	12×	64.2 %

Effort	Sonnet 5.5	Sonnet 5
low	12×	58.5 %	16×	48.3 %
medium	13×	61.7 %	23×	52.8 %
high	18×	66.9 %	33×	55.9 %
xHigh	33×	70.9 %	50×	57.5 %
max	115×	72.8 %	109×	60.1 %

Effort	Sonnet 5.5	Haiku 5.5
low	12×	58.5 %	1.0×	51.0 %
medium	13×	61.7 %	1.4×	55.5 %
high	18×	66.9 %	2.2×	58.6 %
xHigh	33×	70.9 %	4.3×	61.8 %
max	115×	72.8 %	12×	64.2 %

Effort	Sonnet 5	Haiku 5.5
low	16×	48.3 %	1.0×	51.0 %
medium	23×	52.8 %	1.4×	55.5 %
high	33×	55.9 %	2.2×	58.6 %
xHigh	50×	57.5 %	4.3×	61.8 %
max	109×	60.1 %	12×	64.2 %

Every pair, written out

Head-to-headFable 5.1 vs Opus 5.5

Opus 5.5 · Mediummatches Fable 5.1 · Max70.8 % vs 70.6 % · cost 35× vs 293×

8.3×cheaper

Head-to-headFable 5.1 vs Sonnet 5.5

Sonnet 5.5 · xHighmatches Fable 5.1 · Max70.9 % vs 70.6 % · cost 33× vs 293×

8.9×cheaper

Head-to-headFable 5.1 vs Haiku 5.5

Fable 5.1 · Lowmatches Haiku 5.5 · Max64.8 % vs 64.2 % · cost 70× vs 12×

6.0×dearer

Head-to-headOpus 5.5 vs Sonnet 5.5

Opus 5.5 · Highmatches Sonnet 5.5 · Max72.2 % vs 72.8 % · cost 43× vs 115×

2.6×cheaper

Head-to-headOpus 5.5 vs Haiku 5.5

Opus 5.5 · Lowmatches Haiku 5.5 · Max66.0 % vs 64.2 % · cost 25× vs 12×

2.1×dearer

Head-to-headSonnet 5.5 vs Haiku 5.5

Sonnet 5.5 · Highmatches Haiku 5.5 · Max66.9 % vs 64.2 % · cost 18× vs 12×

1.6×dearer

Head-to-headFable 5.1 vs Fable 5

Fable 5.1 · Mediummatches Fable 5 · Max67.2 % vs 67.8 % · cost 84× vs 270×

3.2×cheaper

Head-to-headOpus 5.5 vs Opus 5

Opus 5.5 · Mediummatches Opus 5 · Max70.8 % vs 69.6 % · cost 35× vs 148×

4.2×cheaper

Head-to-headSonnet 5.5 vs Sonnet 5

Sonnet 5.5 · Mediummatches Sonnet 5 · Max61.7 % vs 60.1 % · cost 13× vs 109×

8.5×cheaper

Fable 5.1vsOpus 5.5

Opus 5.5 at Medium gives the same quality as Fable 5.1 at Max for 8.3× less per task.

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Effort	Fable 5.1		Opus 5.5
Effort	cost	score	cost	score
low	70×	64.8 %	25×	66.0 %
medium	84×	67.2 %	35×	70.8 %
high	102×	68.2 %	43×	72.2 %
xHigh	186×	69.8 %	74×	73.9 %
max	293×	70.6 %	194×	74.7 %

Fable 5.1vsSonnet 5.5

Sonnet 5.5 at xHigh gives the same quality as Fable 5.1 at Max for 8.9× less per task.

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Effort	Fable 5.1		Sonnet 5.5
Effort	cost	score	cost	score
low	70×	64.8 %	12×	58.5 %
medium	84×	67.2 %	13×	61.7 %
high	102×	68.2 %	18×	66.9 %
xHigh	186×	69.8 %	33×	70.9 %
max	293×	70.6 %	115×	72.8 %

Fable 5.1vsHaiku 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Effort	Fable 5.1		Haiku 5.5
Effort	cost	score	cost	score
low	70×	64.8 %	1.0×	51.0 %
medium	84×	67.2 %	1.4×	55.5 %
high	102×	68.2 %	2.2×	58.6 %
xHigh	186×	69.8 %	4.3×	61.8 %
max	293×	70.6 %	12×	64.2 %

Opus 5.5vsSonnet 5.5

Opus 5.5 at High gives the same quality as Sonnet 5.5 at Max for 2.6× less per task.

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Effort	Opus 5.5		Sonnet 5.5
Effort	cost	score	cost	score
low	25×	66.0 %	12×	58.5 %
medium	35×	70.8 %	13×	61.7 %
high	43×	72.2 %	18×	66.9 %
xHigh	74×	73.9 %	33×	70.9 %
max	194×	74.7 %	115×	72.8 %

Opus 5.5vsHaiku 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Effort	Opus 5.5		Haiku 5.5
Effort	cost	score	cost	score
low	25×	66.0 %	1.0×	51.0 %
medium	35×	70.8 %	1.4×	55.5 %
high	43×	72.2 %	2.2×	58.6 %
xHigh	74×	73.9 %	4.3×	61.8 %
max	194×	74.7 %	12×	64.2 %

Sonnet 5.5vsHaiku 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Effort	Sonnet 5.5		Haiku 5.5
Effort	cost	score	cost	score
low	12×	58.5 %	1.0×	51.0 %
medium	13×	61.7 %	1.4×	55.5 %
high	18×	66.9 %	2.2×	58.6 %
xHigh	33×	70.9 %	4.3×	61.8 %
max	115×	72.8 %	12×	64.2 %

Fable 5.1vsFable 5

Fable 5.1 at Medium gives the same quality as Fable 5 at Max for 3.2× less per task.

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Effort	Fable 5.1		Fable 5
Effort	cost	score	cost	score
low	70×	64.8 %	69×	60.5 %
medium	84×	67.2 %	95×	64.0 %
high	102×	68.2 %	115×	65.9 %
xHigh	186×	69.8 %	165×	66.9 %
max	293×	70.6 %	270×	67.8 %

Opus 5.5vsOpus 5

Opus 5.5 at Medium gives the same quality as Opus 5 at Max for 4.2× less per task.

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Effort	Opus 5.5		Opus 5
Effort	cost	score	cost	score
low	25×	66.0 %	39×	62.5 %
medium	35×	70.8 %	57×	66.1 %
high	43×	72.2 %	84×	68.0 %
xHigh	74×	73.9 %	111×	69.2 %
max	194×	74.7 %	148×	69.6 %

Sonnet 5.5vsSonnet 5

Sonnet 5.5 at Medium gives the same quality as Sonnet 5 at Max for 8.5× less per task.

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Effort	Sonnet 5.5		Sonnet 5
Effort	cost	score	cost	score
low	12×	58.5 %	16×	48.3 %
medium	13×	61.7 %	23×	52.8 %
high	18×	66.9 %	33×	55.9 %
xHigh	33×	70.9 %	50×	57.5 %
max	115×	72.8 %	109×	60.1 %

Sonnet 5's cost is size-sensitive: a verbose model, its cost swings widely between short and long agentic tasks, hence its wide interval.

How to read these comparisons

The values are the ones the main page shows, fitted from public measurements taken on the same tasks. One model is cheaper or higher than the other at an effort level when the fitted difference puts it ahead with at least 84 % probability, the level of the intervals shown everywhere on the site; otherwise the two are level within the uncertainty. A match is the cheapest setting of the other model that the first does not out-score at that level. Costs are what a whole task cost, as each source measured it (the run's actual spend, cache included), not the price per token. So the cost already counts how many tokens each model uses: a model with a lower price per token can still cost more per task if it writes many more tokens.

Compare two Claude models

Fable 5.1vsOpus 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5.1vsFable 5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5.1vsOpus 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5.1vsOpus 5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5.1vsSonnet 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5.1vsSonnet 5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5.1vsHaiku 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5.1vsHaiku 4.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5vsOpus 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5vsOpus 5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5vsSonnet 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5vsSonnet 5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5vsHaiku 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5vsHaiku 4.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Opus 5.5vsOpus 5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Opus 5.5vsSonnet 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Opus 5.5vsSonnet 5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Opus 5.5vsHaiku 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Opus 5.5vsHaiku 4.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Opus 5vsSonnet 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Opus 5vsSonnet 5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Opus 5vsHaiku 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Opus 5vsHaiku 4.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Sonnet 5.5vsSonnet 5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Sonnet 5.5vsHaiku 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Sonnet 5.5vsHaiku 4.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Sonnet 5vsHaiku 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Sonnet 5vsHaiku 4.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Haiku 5.5vsHaiku 4.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5.1vsOpus 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5.1vsSonnet 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5.1vsHaiku 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Opus 5.5vsSonnet 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Opus 5.5vsHaiku 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Sonnet 5.5vsHaiku 5.5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Fable 5.1vsFable 5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Opus 5.5vsOpus 5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel

Sonnet 5.5vsSonnet 5

By effort level cost per task × the cheapest couple · expected score on the benchmark panel