What is the difference between Grok 3 Beta and xAI: Grok 4 Fast (free)?

Both are developed by xAI but target different use cases. Grok 3 Beta has a 131K token context window vs xAI: Grok 4 Fast (free)'s 2.0M. You can compare their actual outputs across 35 challenges on Rival to see how they differ in practice.

Which is better, Grok 3 Beta or xAI: Grok 4 Fast (free)?

It depends on your use case. Grok 3 Beta and xAI: Grok 4 Fast (free) each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 35 challenges so you can judge which fits your needs best.

How much does Grok 3 Beta cost compared to xAI: Grok 4 Fast (free)?

Grok 3 Beta costs $2/M input tokens and xAI: Grok 4 Fast (free) costs $0/M input tokens. xAI: 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 3 Beta and xAI: Grok 4 Fast (free) on Rival?

This page shows a side-by-side comparison of Grok 3 Beta and xAI: Grok 4 Fast (free) 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 3 Beta and xAI: Grok 4 Fast (free)?

Both are developed by xAI but target different use cases. Grok 3 Beta has a 131K token context window vs xAI: Grok 4 Fast (free)'s 2.0M. You can compare their actual outputs across 35 challenges on Rival to see how they differ in practice.

Which is better, Grok 3 Beta or xAI: Grok 4 Fast (free)?

It depends on your use case. Grok 3 Beta and xAI: Grok 4 Fast (free) each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 35 challenges so you can judge which fits your needs best.

How much does Grok 3 Beta cost compared to xAI: Grok 4 Fast (free)?

Grok 3 Beta costs $2/M input tokens and xAI: Grok 4 Fast (free) costs $0/M input tokens. xAI: 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 3 Beta and xAI: Grok 4 Fast (free) on Rival?

This page shows a side-by-side comparison of Grok 3 Beta and xAI: Grok 4 Fast (free) 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 3 Beta vs xAI: Grok 4 Fast (free): Which Is Better?

Updated Sep 2025

Our Verdict

Grok 3 Beta

xAI: Grok 4 Fast (free)

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

API pricing

Cost per 1M tokens

Grok 3 Beta

Input

$2.00

Output

$4.00

xAI: Grok 4 Fast (free)

Input

$0.000

Output

$0.000

Writing DNA

Style Comparison

Similarity

57%

xAI: Grok 4 Fast (free) uses 3.0x more headings

Grok 3 Beta

xAI: Grok 4 Fast (free)

48%Vocabulary65%

19wSentence Length13w

0.67Hedging0.56

3.1Bold1.4

5.5Lists2.5

0.00Emoji0.00

0.52Headings1.58

0.28Transitions0.28

Based on 23 + 14 text responses

Research

What we learned reading every model

Grok 3 Beta and xAI: Grok 4 Fast (free) have opinions about your brand too.Ask 10 models what they tell people about you. Verbatim receipts.Run the mirror

FAQ

Common questions

Keep exploring

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Grok 3 Beta vs Llama 4 MaverickNew provider

Updated Sep 2025

Our Verdict

Grok 3 Beta

xAI: Grok 4 Fast (free)

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

API pricing

Cost per 1M tokens

Grok 3 Beta

Input

$2.00

Output

$4.00

xAI: Grok 4 Fast (free)

Input

$0.000

Output

$0.000

Writing DNA

Style Comparison

Similarity

57%

xAI: Grok 4 Fast (free) uses 3.0x more headings

Grok 3 Beta

xAI: Grok 4 Fast (free)

48%Vocabulary65%

19wSentence Length13w

0.67Hedging0.56

3.1Bold1.4

5.5Lists2.5

0.00Emoji0.00

0.52Headings1.58

0.28Transitions0.28

Based on 23 + 14 text responses

Research

What we learned reading every model

Grok 3 Beta and xAI: Grok 4 Fast (free) have opinions about your brand too.Ask 10 models what they tell people about you. Verbatim receipts.Run the mirror

FAQ

Common questions

Keep exploring

More comparisons

Grok 3 Beta vs MiniMax M3New provider

Grok 3 Beta vs OpenAI o3New provider

Grok 3 Beta vs Llama 4 MaverickNew provider