Claude Fable 5.1 vs Claude Sonnet 5.5

Which is the better AI model in 2026? Here's how they compare.

Claude Fable 5.1
Anthropic
53.4
Intelligence Index
View Claude Fable 5.1
Higher intelligence
Claude Sonnet 5.5
Anthropic
56
Intelligence Index
View Claude Sonnet 5.5

Capability profile

Artificial Analysis indices (0–100). Missing dimensions show as 0.

Head to head

Claude Fable 5.1
Claude Sonnet 5.5
Intelligence
53.4
56
Coding
81.6
—
Math
—
—
Context window
1,000,000
1,000,000
Output price
$50/1M
$10/1M
Input price
$10/1M
$2/1M
Speed (t/s)
66
130
Knowledge cutoff
2026-06
2026-06
Open weights
No
No
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