What is the difference between GPT-5.1 Chat and Grok 4.5?

GPT-5.1 Chat is developed by OpenAI while Grok 4.5 is developed by xAI. GPT-5.1 Chat has a 128K token context window vs Grok 4.5's 500K. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.1 Chat or Grok 4.5?

It depends on your use case. GPT-5.1 Chat and Grok 4.5 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 52 challenges so you can judge which fits your needs best.

How much does GPT-5.1 Chat cost compared to Grok 4.5?

GPT-5.1 Chat costs $1.25/M input tokens and Grok 4.5 costs $2/M input tokens. GPT-5.1 Chat is $0.75/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 GPT-5.1 Chat and Grok 4.5 on Rival?

This page shows a side-by-side comparison of GPT-5.1 Chat and Grok 4.5 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 GPT-5.1 Chat and Grok 4.5?

GPT-5.1 Chat is developed by OpenAI while Grok 4.5 is developed by xAI. GPT-5.1 Chat has a 128K token context window vs Grok 4.5's 500K. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.1 Chat or Grok 4.5?

It depends on your use case. GPT-5.1 Chat and Grok 4.5 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 52 challenges so you can judge which fits your needs best.

How much does GPT-5.1 Chat cost compared to Grok 4.5?

GPT-5.1 Chat costs $1.25/M input tokens and Grok 4.5 costs $2/M input tokens. GPT-5.1 Chat is $0.75/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 GPT-5.1 Chat and Grok 4.5 on Rival?

This page shows a side-by-side comparison of GPT-5.1 Chat and Grok 4.5 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.

GPT-5.1 Chat vs Grok 4.5: Which Is Better?

Updated Jul 2026

Our Verdict

Grok 4.5

GPT-5.1 ChatRunner-up

No community votes yet. On paper, Grok 4.5 has the edge — newer, bigger context window.

Too close to call

What do GPT-5.1 Chat and Grok 4.5 say about your brand?

10 models, one question, verbatim receipts.

or peek at a demo: Notion Linear Vercel

API pricing

Cost per 1M tokens

GPT-5.1 Chat

Input

$1.25

1.6× cheaper

Output

$10.00

Grok 4.5

Input

$2.00

Output

$6.00

1.7× cheaper

GPT-5.1 Chat wins input (1.6× cheaper)·Grok 4.5 wins output (1.7× cheaper)

Writing DNA

Style Comparison

Similarity

63%

Grok 4.5 uses 9.0x more emoji

GPT-5.1 Chat

Grok 4.5

73%Vocabulary61%

18wSentence Length16w

0.45Hedging0.23

1.1Bold2.5

2.4Lists2.4

0.00Emoji0.09

0.00Headings0.48

0.06Transitions0.06

Based on 15 + 27 text responses

Research

What we learned reading every model

FAQ

Common questions

Keep exploring

More comparisons

GPT-5.1 Chat vs MiniMax M3New provider

GPT-5.1 Chat vs Ox AlphaNew provider

GPT-5.1 Chat vs Claude Sonnet 4New provider

Updated Jul 2026

Our Verdict

Grok 4.5

GPT-5.1 ChatRunner-up

No community votes yet. On paper, Grok 4.5 has the edge — newer, bigger context window.

Too close to call

What do GPT-5.1 Chat and Grok 4.5 say about your brand?

10 models, one question, verbatim receipts.

or peek at a demo: Notion Linear Vercel

API pricing

Cost per 1M tokens

GPT-5.1 Chat

Input

$1.25

1.6× cheaper

Output

$10.00

Grok 4.5

Input

$2.00

Output

$6.00

1.7× cheaper

GPT-5.1 Chat wins input (1.6× cheaper)·Grok 4.5 wins output (1.7× cheaper)

Writing DNA

Style Comparison

Similarity

63%

Grok 4.5 uses 9.0x more emoji

GPT-5.1 Chat

Grok 4.5

73%Vocabulary61%

18wSentence Length16w

0.45Hedging0.23

1.1Bold2.5

2.4Lists2.4

0.00Emoji0.09

0.00Headings0.48

0.06Transitions0.06

Based on 15 + 27 text responses

Research

What we learned reading every model

FAQ

Common questions

Keep exploring

More comparisons

GPT-5.1 Chat vs MiniMax M3New provider

GPT-5.1 Chat vs Ox AlphaNew provider

GPT-5.1 Chat vs Claude Sonnet 4New provider