What is the difference between GPT-4.5 and GPT-5.1-Codex-Mini?

Both are developed by OpenAI but target different use cases. GPT-4.5 has a 128K token context window vs GPT-5.1-Codex-Mini's 400K. You can compare their actual outputs across 25 challenges on Rival to see how they differ in practice.

Which is better, GPT-4.5 or GPT-5.1-Codex-Mini?

It depends on your use case. GPT-4.5 and GPT-5.1-Codex-Mini each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 25 challenges so you can judge which fits your needs best.

How much does GPT-4.5 cost compared to GPT-5.1-Codex-Mini?

GPT-4.5 costs $75/M input tokens and GPT-5.1-Codex-Mini costs $1.5/M input tokens. GPT-5.1-Codex-Mini is $73.50/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-4.5 and GPT-5.1-Codex-Mini on Rival?

This page shows a side-by-side comparison of GPT-4.5 and GPT-5.1-Codex-Mini 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-4.5 and GPT-5.1-Codex-Mini?

Both are developed by OpenAI but target different use cases. GPT-4.5 has a 128K token context window vs GPT-5.1-Codex-Mini's 400K. You can compare their actual outputs across 25 challenges on Rival to see how they differ in practice.

Which is better, GPT-4.5 or GPT-5.1-Codex-Mini?

It depends on your use case. GPT-4.5 and GPT-5.1-Codex-Mini each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 25 challenges so you can judge which fits your needs best.

How much does GPT-4.5 cost compared to GPT-5.1-Codex-Mini?

GPT-4.5 costs $75/M input tokens and GPT-5.1-Codex-Mini costs $1.5/M input tokens. GPT-5.1-Codex-Mini is $73.50/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-4.5 and GPT-5.1-Codex-Mini on Rival?

This page shows a side-by-side comparison of GPT-4.5 and GPT-5.1-Codex-Mini 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-4.5 vs GPT-5.1-Codex-Mini: Which Is Better?

Updated Nov 2025

Our Verdict

GPT-5.1-Codex-Mini

GPT-4.5Runner-up

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

GPT-5.1-Codex-Mini is 25x cheaper per token — worth considering if cost matters.

Too close to call

API pricing

Cost per 1M tokens

GPT-4.5

Input

$75.00

Output

$150.00

GPT-5.1-Codex-Mini

Input

$1.50

50× cheaper

Output

$6.00

25× cheaper

GPT-5.1-Codex-Mini is cheaper on both — 50× input, 25× output

Writing DNA

Style Comparison

Similarity

41%

GPT-4.5 uses 16.8x more headings

GPT-4.5

GPT-5.1-Codex-Mini

63%Vocabulary65%

16wSentence Length20w

0.57Hedging0.56

4.7Bold3.3

6.4Lists3.4

0.00Emoji0.00

1.30Headings0.08

0.54Transitions0.05

Based on 11 + 13 text responses

Research

What we learned reading every model

GPT-4.5 and GPT-5.1-Codex-Mini 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-4.5 vs Llama 4 MaverickNew provider

GPT-5.1-Codex-Mini vs GPT-5Same lab

GPT-4.5 vs MiniMax M3New provider

Updated Nov 2025

Our Verdict

GPT-5.1-Codex-Mini

GPT-4.5Runner-up

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

GPT-5.1-Codex-Mini is 25x cheaper per token — worth considering if cost matters.

Too close to call

API pricing

Cost per 1M tokens

GPT-4.5

Input

$75.00

Output

$150.00

GPT-5.1-Codex-Mini

Input

$1.50

50× cheaper

Output

$6.00

25× cheaper

GPT-5.1-Codex-Mini is cheaper on both — 50× input, 25× output

Writing DNA

Style Comparison

Similarity

41%

GPT-4.5 uses 16.8x more headings

GPT-4.5

GPT-5.1-Codex-Mini

63%Vocabulary65%

16wSentence Length20w

0.57Hedging0.56

4.7Bold3.3

6.4Lists3.4

0.00Emoji0.00

1.30Headings0.08

0.54Transitions0.05

Based on 11 + 13 text responses

Research

What we learned reading every model

GPT-4.5 and GPT-5.1-Codex-Mini 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-4.5 vs Llama 4 MaverickNew provider

GPT-5.1-Codex-Mini vs GPT-5Same lab

GPT-4.5 vs MiniMax M3New provider