What is the difference between Gemini 2.5 Flash Preview and GPT-5.1?

Gemini 2.5 Flash Preview is developed by Google AI while GPT-5.1 is developed by OpenAI. Gemini 2.5 Flash Preview has a 1.0M token context window vs GPT-5.1's 400K. You can compare their actual outputs across 27 challenges on Rival to see how they differ in practice.

Which is better, Gemini 2.5 Flash Preview or GPT-5.1?

It depends on your use case. Gemini 2.5 Flash Preview and GPT-5.1 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 27 challenges so you can judge which fits your needs best.

How much does Gemini 2.5 Flash Preview cost compared to GPT-5.1?

Gemini 2.5 Flash Preview costs $0.15/M input tokens and GPT-5.1 costs $1.25/M input tokens. Gemini 2.5 Flash Preview is $1.10/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 Gemini 2.5 Flash Preview and GPT-5.1 on Rival?

This page shows a side-by-side comparison of Gemini 2.5 Flash Preview and GPT-5.1 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 Gemini 2.5 Flash Preview and GPT-5.1?

Gemini 2.5 Flash Preview is developed by Google AI while GPT-5.1 is developed by OpenAI. Gemini 2.5 Flash Preview has a 1.0M token context window vs GPT-5.1's 400K. You can compare their actual outputs across 27 challenges on Rival to see how they differ in practice.

Which is better, Gemini 2.5 Flash Preview or GPT-5.1?

It depends on your use case. Gemini 2.5 Flash Preview and GPT-5.1 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 27 challenges so you can judge which fits your needs best.

How much does Gemini 2.5 Flash Preview cost compared to GPT-5.1?

Gemini 2.5 Flash Preview costs $0.15/M input tokens and GPT-5.1 costs $1.25/M input tokens. Gemini 2.5 Flash Preview is $1.10/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 Gemini 2.5 Flash Preview and GPT-5.1 on Rival?

This page shows a side-by-side comparison of Gemini 2.5 Flash Preview and GPT-5.1 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.

Updated Nov 2025

Gemini 2.5 Flash PreviewvsGPT-5.1

Gemini 2.5 Flash Preview is cheaper than GPT-5.1 at $0.15/M vs $1.25/M input tokens.

Gemini 2.5 Flash Preview and GPT-5.1 compared across 27 shared prompts
Spec	Gemini 2.5 Flash Preview	GPT-5.1
Input price	$0.15/M tokens	$1.25/M tokens
Output price	$0.6/M tokens	$10/M tokens
Context window	1.0M tokens	400K tokens
Released	Apr 2025	Nov 2025
SWE-bench Verified	60.4%	76.3%

Our Verdict

GPT-5.1

Gemini 2.5 Flash PreviewRunner-up

Not enough votes to call it. On the specs, GPT-5.1 has the edge: bigger model tier, newer.

Gemini 2.5 Flash Preview costs 17x less per token.

Too close to call

API pricing

Cost per 1M tokens

Gemini 2.5 Flash Preview

Input

$0.15

8.3× cheaper

Output

$0.60

17× cheaper

GPT-5.1

Input

$1.25

Output

$10.00

Gemini 2.5 Flash Preview is cheaper on both — 8.3× input, 17× output

Writing DNA

Style Comparison

Similarity

47%

Gemini 2.5 Flash Preview uses 8.7x more transitions

Gemini 2.5 Flash Preview

GPT-5.1

51%Vocabulary62%

15wSentence Length19w

0.70Hedging0.29

4.1Bold3.5

3.3Lists7.2

0.00Emoji0.00

0.09Headings0.61

0.24Transitions0.03

Based on 12 + 14 text responses

Research

What we learned reading every model

FAQ

Common questions

Keep exploring

More comparisons

Gemini 2.5 Flash Preview vs Ox AlphaNew provider

Gemini 2.5 Flash Preview vs Claude Opus 4New provider

Gemini 2.5 Flash Preview vs Claude Opus 4.1New provider

Gemini 2.5 Flash Preview vs Grok 3New provider

Gemini 2.5 Flash Preview vs Owl AlphaNew provider

GPT-5.1 vs PaLM 2 ChatCross-provider

Gemini 2.5 Flash Preview vs Polaris AlphaNew provider

Gemini 2.5 Flash Preview vs Pony AlphaNew provider

Updated Nov 2025

Gemini 2.5 Flash PreviewvsGPT-5.1

Gemini 2.5 Flash Preview is cheaper than GPT-5.1 at $0.15/M vs $1.25/M input tokens.

Gemini 2.5 Flash Preview and GPT-5.1 compared across 27 shared prompts
Spec	Gemini 2.5 Flash Preview	GPT-5.1
Input price	$0.15/M tokens	$1.25/M tokens
Output price	$0.6/M tokens	$10/M tokens
Context window	1.0M tokens	400K tokens
Released	Apr 2025	Nov 2025
SWE-bench Verified	60.4%	76.3%

Our Verdict

GPT-5.1

Gemini 2.5 Flash PreviewRunner-up

Not enough votes to call it. On the specs, GPT-5.1 has the edge: bigger model tier, newer.

Gemini 2.5 Flash Preview costs 17x less per token.

Too close to call

API pricing

Cost per 1M tokens

Gemini 2.5 Flash Preview

Input

$0.15

8.3× cheaper

Output

$0.60

17× cheaper

GPT-5.1

Input

$1.25

Output

$10.00

Gemini 2.5 Flash Preview is cheaper on both — 8.3× input, 17× output

Writing DNA

Style Comparison

Similarity

47%

Gemini 2.5 Flash Preview uses 8.7x more transitions

Gemini 2.5 Flash Preview

GPT-5.1

51%Vocabulary62%

15wSentence Length19w

0.70Hedging0.29

4.1Bold3.5

3.3Lists7.2

0.00Emoji0.00

0.09Headings0.61

0.24Transitions0.03

Based on 12 + 14 text responses

Research

What we learned reading every model

FAQ

Common questions

Keep exploring

More comparisons

Gemini 2.5 Flash Preview vs Ox AlphaNew provider

Gemini 2.5 Flash Preview vs Claude Opus 4New provider

Gemini 2.5 Flash Preview vs Claude Opus 4.1New provider

Gemini 2.5 Flash Preview vs Grok 3New provider

Gemini 2.5 Flash Preview vs Owl AlphaNew provider

GPT-5.1 vs PaLM 2 ChatCross-provider

Gemini 2.5 Flash Preview vs Polaris AlphaNew provider

Gemini 2.5 Flash Preview vs Pony AlphaNew provider