ClaudevsGrok

Claude Opus 5.5 vs Grok 4.20 Reasoning

Side-by-side comparison of pricing, task quality, and projected cost at higher scale.

Pricing

Side-by-side pricing

Claude Opus 5.5

Flagship

Grok 4.20 Reasoning

Mid-tier
Input $/MTok
$4.00
$1.25
Output $/MTok
$20.00
$2.50
Cache discount
95% off
84% off
Context
1,000K
1,000K

Quality

Task confidence comparison

Confidence score from zero to one hundred by task type, where higher is better.
Code Generation
0
vs
0
Code Review
0
vs
0
Summarization
0
vs
0
Q&A
0
vs
0
Extraction
0
vs
0
Reasoning
0
vs
0
Classification
0
vs
0
Creative Writing
0
vs
0
Claude Opus 5.5
Grok 4.20 Reasoning

Guidance

When to use Claude Opus 5.5 vs Grok 4.20 Reasoning

Choose Claude Opus 5.5 when...

  • Similar performance; consider provider preference or ecosystem fit.

Choose Grok 4.20 Reasoning when...

  • -Cost matters: 69% cheaper on input tokens

At scale

Cost at scale

Estimated cost assuming a seventy percent input and thirty percent output token split.
Claude Opus 5.5
Grok 4.20 Reasoning
100K tokens
$0.88
$0.16Cheaper
1M tokens
$8.80
$3.25Cheaper
10M tokens
$88.00
$32.50Cheaper

FAQ

When should I use Claude Opus 5.5 instead of Grok 4.20 Reasoning?

Claude Opus 5.5 and Grok 4.20 Reasoning perform similarly across all tracked tasks. Pick based on pricing and provider preference.

Is Grok 4.20 Reasoning cheaper than Claude Opus 5.5?

Yes. Grok 4.20 Reasoning input costs $1.25/MTok vs $4.00/MTok for Claude Opus 5.5, saving 69% on input.

What are the context window sizes for Claude Opus 5.5 and Grok 4.20 Reasoning?

Claude Opus 5.5 has a 1,000K token context window. Grok 4.20 Reasoning has a 1,000K token context window.

Track your real costs

Comparisons show estimated costs at list price. The dashboard reveals your real spend and savings.