Claude Opus 4.6 vs Claude Opus 4.5

API pricing, benchmark indices and specs — updated 19 October 2026.

anthropic · A · API-only
Input / 1M
$5.00
Output / 1M
$25.00
AA index
31.9
proprietary · 1M context
anthropic · B · API-only
Input / 1M
$5.00
Output / 1M
$25.00
AA index
29.1
proprietary · 200K context

Specification comparison

Differences are highlighted; identical values are muted.

Specification Claude Opus 4.6 Claude Opus 4.5
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 1,000,000 200,000
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 $5.00 $5.00
API output price / 1M tokens $25.00 $25.00
Est. cost per 1M input + 1M output tokens $30.00 $30.00
Cached input / 1M tokens $0.50 $0.50
AA Intelligence Index 31.9 29.1
AA Coding Index — —
AA Agentic Index — —
Max output tokens 128,000 64,000
API providers 5 5
Tool calling Yes Yes
Reasoning mode Yes Yes

API cost

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

Claude Opus 4.6 $30.00
Claude Opus 4.5 $30.00

Adjacent comparisons