Claude Fable 5.2 vs Claude Opus 5.5

API pricing, benchmark indices and specs — updated 10 November 2026.

anthropic · A · API-only
Input / 1M
$8.00
Output / 1M
$40.00
AA index
64.6
proprietary · 1M context
anthropic · B · API-only
Input / 1M
$4.00
Output / 1M
$20.00
AA index
59.1
proprietary · 1M context

Specification comparison

Differences are highlighted; identical values are muted.

Specification Claude Fable 5.2 Claude Opus 5.5
Deployment API-only (closed weights) API-only (closed weights)
Parameters n/a — API-only n/a — API-only
Architecture n/a — API-only n/a — API-only
Context length 1,000,000 1,000,000
Licence Proprietary Proprietary
Commercial use Per API terms Per API terms
Languages n/a — API-only n/a — API-only
Downloads 30d n/a — API-only n/a — API-only
Downloads all time n/a — API-only n/a — API-only
Quantizations on the Hub n/a — API-only n/a — API-only
Gated n/a — API-only n/a — API-only
First seen on the Hub n/a — API-only n/a — API-only
API input price / 1M tokens $8.00 $4.00
API output price / 1M tokens $40.00 $20.00
Est. cost per 1M input + 1M output tokens $48.00 $24.00
Cached input / 1M tokens $0.20 $0.20
AA Intelligence Index 64.6 59.1
AA Coding Index — —
AA Agentic Index — —
Max output tokens 128,000 128,000
API providers 4 5
Tool calling Yes Yes
Reasoning mode Yes Yes

API cost

Estimated cost of 1M input + 1M output tokens via OpenRouter

Claude Fable 5.2 $48.00
Claude Opus 5.5 $24.00

Claude Opus 5.5 is 2.0× cheaper at list price.

Adjacent comparisons