Compare AI models

Specifications
Context window
1M—
API pricing
Input price
$4.00$1.25
Output price
$20.00$2.50
Cached input price
$0.20$0.20
Cheapest input
$4.00Amazon Bedrock—
Cheapest output
$20.00Amazon Bedrock—
Benchmarks
BullshitBench v2
63%56%
ARC-AGI-2
91.7%53.3%
Overview
CompanyAnthropicSpaceXAI
Release dateSep 22 2026Feb 17 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Opus 5.5 leads Grok 4.20 Beta on 2 of the 2 benchmarks they both report (BullshitBench v2, ARC-AGI-2). Grok 4.20 Beta is cheaper on both input and output: $1.25 vs $4.00 per million input tokens, and $2.50 vs $20.00 per million output tokens. Figures are base-tier rates. Grok 4.20 Beta shipped 217 days before Claude Opus 5.5, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

On BullshitBench v2, Claude Opus 5.5 leads at 63% vs Grok 4.20 Beta at 56%. On ARC-AGI-2, Claude Opus 5.5 leads at 91.7% vs Grok 4.20 Beta at 53.3%.