Grok 4.5 vs Claude Sonnet 5

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

x-ai · A · API-only
Input / 1M
$2.00
Output / 1M
$6.00
AA index
38.8
proprietary · 500K context
anthropic · B · API-only
Input / 1M
$2.00
Output / 1M
$10.00
AA index
38.2
proprietary · 1M context

Specification comparison

Differences are highlighted; identical values are muted.

Specification Grok 4.5 Claude Sonnet 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 500,000 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 $2.00 $2.00
API output price / 1M tokens $6.00 $10.00
Est. cost per 1M input + 1M output tokens $8.00 $12.00
Cached input / 1M tokens $0.30 $0.20
AA Intelligence Index 38.8 38.2
AA Coding Index 72.4 71.5
AA Agentic Index 41.2 43.6
Max output tokens 450,000 128,000
API providers 1 5
Tool calling Yes Yes
Reasoning mode Yes Yes

API cost

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

Grok 4.5 $8.00
Claude Sonnet 5 $12.00

Grok 4.5 is 1.5× cheaper at list price.

Adjacent comparisons