What is the difference between Grok 4 Fast (free) and Grok 4.6?

Both are developed by xAI but target different use cases. Grok 4 Fast (free) has a 2.0M token context window vs Grok 4.6's 500K. You can compare their actual outputs across 34 challenges on Rival to see how they differ in practice.

Which is better, Grok 4 Fast (free) or Grok 4.6?

It depends on your use case. Grok 4 Fast (free) and Grok 4.6 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 34 challenges so you can judge which fits your needs best.

How much does Grok 4 Fast (free) cost compared to Grok 4.6?

Grok 4 Fast (free) costs $0/M input tokens and Grok 4.6 costs $2/M input tokens. Grok 4 Fast (free) is $2.00/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

How can I compare Grok 4 Fast (free) and Grok 4.6 on Rival?

This page shows a side-by-side comparison of Grok 4 Fast (free) and Grok 4.6 across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.

What is the difference between Grok 4 Fast (free) and Grok 4.6?

Both are developed by xAI but target different use cases. Grok 4 Fast (free) has a 2.0M token context window vs Grok 4.6's 500K. You can compare their actual outputs across 34 challenges on Rival to see how they differ in practice.

Which is better, Grok 4 Fast (free) or Grok 4.6?

It depends on your use case. Grok 4 Fast (free) and Grok 4.6 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 34 challenges so you can judge which fits your needs best.

How much does Grok 4 Fast (free) cost compared to Grok 4.6?

Grok 4 Fast (free) costs $0/M input tokens and Grok 4.6 costs $2/M input tokens. Grok 4 Fast (free) is $2.00/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

How can I compare Grok 4 Fast (free) and Grok 4.6 on Rival?

This page shows a side-by-side comparison of Grok 4 Fast (free) and Grok 4.6 across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.

Grok 4 Fast (free) vs Grok 4.6: Which Is Better?

Updated Aug 2026

Our Verdict

Grok 4 Fast (free)

Grok 4.6

No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.

Too close to call

What do Grok 4 Fast (free) and Grok 4.6 say about your brand?

10 models, one question, verbatim receipts.

or peek at a demo: Notion Linear Vercel

API pricing

Cost per 1M tokens

Grok 4 Fast (free)

Input

$0.000

Output

$0.000

Grok 4.6

Input

$2.00

Output

$6.00

Writing DNA

Style Comparison

Similarity

70%

Grok 4.6 uses 29.3x more emoji

Grok 4 Fast (free)

Grok 4.6

65%Vocabulary64%

13wSentence Length17w

0.56Hedging0.22

1.4Bold2.2

2.5Lists1.6

0.00Emoji0.29

1.58Headings0.31

0.28Transitions0.22

Based on 14 + 27 text responses

Research

What we learned reading every model

FAQ

Common questions

Keep exploring

More comparisons

Grok 4 Fast (free) vs MiniMax M3New provider

Grok 4 Fast (free) vs GPT-5New provider

Grok 4 Fast (free) vs Claude Sonnet 4New provider

Updated Aug 2026

Our Verdict

Grok 4 Fast (free)

Grok 4.6

No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.

Too close to call

What do Grok 4 Fast (free) and Grok 4.6 say about your brand?

10 models, one question, verbatim receipts.

or peek at a demo: Notion Linear Vercel

API pricing

Cost per 1M tokens

Grok 4 Fast (free)

Input

$0.000

Output

$0.000

Grok 4.6

Input

$2.00

Output

$6.00

Writing DNA

Style Comparison

Similarity

70%

Grok 4.6 uses 29.3x more emoji

Grok 4 Fast (free)

Grok 4.6

65%Vocabulary64%

13wSentence Length17w

0.56Hedging0.22

1.4Bold2.2

2.5Lists1.6

0.00Emoji0.29

1.58Headings0.31

0.28Transitions0.22

Based on 14 + 27 text responses

Research

What we learned reading every model

FAQ

Common questions

Keep exploring

More comparisons

Grok 4 Fast (free) vs MiniMax M3New provider

Grok 4 Fast (free) vs GPT-5New provider

Grok 4 Fast (free) vs Claude Sonnet 4New provider