What is the difference between GPT-5.1 and o1?

Both are developed by OpenAI but target different use cases. GPT-5.1 has a 400K token context window vs o1's 128K. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.1 or o1?

It depends on your use case. GPT-5.1 and o1 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 cost compared to o1?

GPT-5.1 costs $1.25/M input tokens and o1 costs $15/M input tokens. GPT-5.1 is $13.75/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 and o1 on Rival?

This page shows a side-by-side comparison of GPT-5.1 and o1 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 and o1?

Both are developed by OpenAI but target different use cases. GPT-5.1 has a 400K token context window vs o1's 128K. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.1 or o1?

It depends on your use case. GPT-5.1 and o1 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 cost compared to o1?

GPT-5.1 costs $1.25/M input tokens and o1 costs $15/M input tokens. GPT-5.1 is $13.75/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 and o1 on Rival?

This page shows a side-by-side comparison of GPT-5.1 and o1 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 vs o1: Which Is Better?

Updated Nov 2025

Our Verdict

GPT-5.1

o1Runner-up

No community votes yet. On paper, GPT-5.1 has the edge — bigger model tier, newer, bigger context window.

GPT-5.1 is 6.0x cheaper per token — worth considering if cost matters.

Slight edge

API pricing

Cost per 1M tokens

GPT-5.1

Input

$1.25

12× cheaper

Output

$10.00

6.0× cheaper

Input

$15.00

Output

$60.00

GPT-5.1 is cheaper on both — 12× input, 6.0× output

Writing DNA

Style Comparison

Similarity

67%

o1 uses 14.5x more transitions

GPT-5.1

62%Vocabulary64%

19wSentence Length16w

0.29Hedging0.76

3.5Bold5.0

7.2Lists2.6

0.00Emoji0.00

0.61Headings0.44

0.03Transitions0.40

Based on 14 + 13 text responses

Research

What we learned reading every model

GPT-5.1 and o1 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

o1 vs MiniMax M3New provider

o1 vs Grok 3New provider

o1 vs Llama 4 MaverickNew provider

Updated Nov 2025

Our Verdict

GPT-5.1

o1Runner-up

No community votes yet. On paper, GPT-5.1 has the edge — bigger model tier, newer, bigger context window.

GPT-5.1 is 6.0x cheaper per token — worth considering if cost matters.

Slight edge

API pricing

Cost per 1M tokens

GPT-5.1

Input

$1.25

12× cheaper

Output

$10.00

6.0× cheaper

Input

$15.00

Output

$60.00

GPT-5.1 is cheaper on both — 12× input, 6.0× output

Writing DNA

Style Comparison

Similarity

67%

o1 uses 14.5x more transitions

GPT-5.1

62%Vocabulary64%

19wSentence Length16w

0.29Hedging0.76

3.5Bold5.0

7.2Lists2.6

0.00Emoji0.00

0.61Headings0.44

0.03Transitions0.40

Based on 14 + 13 text responses

Research

What we learned reading every model

GPT-5.1 and o1 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

o1 vs MiniMax M3New provider

o1 vs Grok 3New provider

o1 vs Llama 4 MaverickNew provider