What is the difference between Gemini 3.5 Flash and GPT-4o (Omni)?

Gemini 3.5 Flash is developed by Google AI while GPT-4o (Omni) is developed by OpenAI. Gemini 3.5 Flash has a 1.0M token context window vs GPT-4o (Omni)'s 128K. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

Which is better, Gemini 3.5 Flash or GPT-4o (Omni)?

It depends on your use case. Gemini 3.5 Flash and GPT-4o (Omni) each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 53 challenges so you can judge which fits your needs best.

How much does Gemini 3.5 Flash cost compared to GPT-4o (Omni)?

Gemini 3.5 Flash costs $1.5/M input tokens and GPT-4o (Omni) costs $2.5/M input tokens. Gemini 3.5 Flash is $1.00/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 Gemini 3.5 Flash and GPT-4o (Omni) on Rival?

This page shows a side-by-side comparison of Gemini 3.5 Flash and GPT-4o (Omni) 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 3.5 Flash and GPT-4o (Omni)?

Gemini 3.5 Flash is developed by Google AI while GPT-4o (Omni) is developed by OpenAI. Gemini 3.5 Flash has a 1.0M token context window vs GPT-4o (Omni)'s 128K. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

Which is better, Gemini 3.5 Flash or GPT-4o (Omni)?

It depends on your use case. Gemini 3.5 Flash and GPT-4o (Omni) each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 53 challenges so you can judge which fits your needs best.

How much does Gemini 3.5 Flash cost compared to GPT-4o (Omni)?

Gemini 3.5 Flash costs $1.5/M input tokens and GPT-4o (Omni) costs $2.5/M input tokens. Gemini 3.5 Flash is $1.00/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 Gemini 3.5 Flash and GPT-4o (Omni) on Rival?

This page shows a side-by-side comparison of Gemini 3.5 Flash and GPT-4o (Omni) 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.

Gemini 3.5 Flash vs GPT-4o (Omni): Which Is Better?

Updated May 2026

Our Verdict

Gemini 3.5 Flash

GPT-4o (Omni)

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

Gemini 3.5 Flash

Input

$1.50

1.7× cheaper

Output

$9.00

1.1× cheaper

GPT-4o (Omni)

Input

$2.50

Output

$10.00

Gemini 3.5 Flash is cheaper on both — 1.7× input, 1.1× output

Writing DNA

Style Comparison

Similarity

33%

GPT-4o (Omni) uses 2.5x more emoji

Gemini 3.5 Flash

GPT-4o (Omni)

59%Vocabulary54%

18wSentence Length18w

0.16Hedging0.72

4.4Bold7.3

3.0Lists5.6

0.00Emoji0.03

0.89Headings1.40

0.11Transitions0.26

Based on 27 + 24 text responses

Research

What we learned reading every model

Gemini 3.5 Flash and GPT-4o (Omni) 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

GPT-4o (Omni) vs MiniMax M3New provider

Gemini 3.5 Flash vs GPT-5Cross-provider

GPT-4o (Omni) vs Llama 4 MaverickNew provider

Updated May 2026

Our Verdict

Gemini 3.5 Flash

GPT-4o (Omni)

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

Gemini 3.5 Flash

Input

$1.50

1.7× cheaper

Output

$9.00

1.1× cheaper

GPT-4o (Omni)

Input

$2.50

Output

$10.00

Gemini 3.5 Flash is cheaper on both — 1.7× input, 1.1× output

Writing DNA

Style Comparison

Similarity

33%

GPT-4o (Omni) uses 2.5x more emoji

Gemini 3.5 Flash

GPT-4o (Omni)

59%Vocabulary54%

18wSentence Length18w

0.16Hedging0.72

4.4Bold7.3

3.0Lists5.6

0.00Emoji0.03

0.89Headings1.40

0.11Transitions0.26

Based on 27 + 24 text responses

Research

What we learned reading every model

Gemini 3.5 Flash and GPT-4o (Omni) 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

GPT-4o (Omni) vs MiniMax M3New provider

Gemini 3.5 Flash vs GPT-5Cross-provider

GPT-4o (Omni) vs Llama 4 MaverickNew provider