What is the difference between GPT-5.1-Codex and OpenAI: GPT-5.6 Sol?

Both are developed by OpenAI but target different use cases. GPT-5.1-Codex has a 400K token context window vs OpenAI: GPT-5.6 Sol's 1.1M. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.1-Codex or OpenAI: GPT-5.6 Sol?

It depends on your use case. GPT-5.1-Codex and OpenAI: GPT-5.6 Sol 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-Codex cost compared to OpenAI: GPT-5.6 Sol?

GPT-5.1-Codex costs $1.25/M input tokens and OpenAI: GPT-5.6 Sol costs $5/M input tokens. GPT-5.1-Codex is $3.75/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-Codex and OpenAI: GPT-5.6 Sol on Rival?

This page shows a side-by-side comparison of GPT-5.1-Codex and OpenAI: GPT-5.6 Sol 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-Codex and OpenAI: GPT-5.6 Sol?

Both are developed by OpenAI but target different use cases. GPT-5.1-Codex has a 400K token context window vs OpenAI: GPT-5.6 Sol's 1.1M. You can compare their actual outputs across 52 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.1-Codex or OpenAI: GPT-5.6 Sol?

It depends on your use case. GPT-5.1-Codex and OpenAI: GPT-5.6 Sol 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-Codex cost compared to OpenAI: GPT-5.6 Sol?

GPT-5.1-Codex costs $1.25/M input tokens and OpenAI: GPT-5.6 Sol costs $5/M input tokens. GPT-5.1-Codex is $3.75/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-Codex and OpenAI: GPT-5.6 Sol on Rival?

This page shows a side-by-side comparison of GPT-5.1-Codex and OpenAI: GPT-5.6 Sol 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-Codex vs OpenAI: GPT-5.6 Sol: Which Is Better?

Updated Jul 2026

Our Verdict

OpenAI: GPT-5.6 Sol

GPT-5.1-CodexRunner-up

No community votes yet. On paper, OpenAI: GPT-5.6 Sol has the edge — newer, bigger context window.

GPT-5.1-Codex is 3.0x cheaper per token — worth considering if cost matters.

Too close to call

API pricing

Cost per 1M tokens

GPT-5.1-Codex

Input

$1.25

4.0× cheaper

Output

$10.00

3.0× cheaper

OpenAI: GPT-5.6 Sol

Input

$5.00

Output

$30.00

GPT-5.1-Codex is cheaper on both — 4.0× input, 3.0× output

Writing DNA

Style Comparison

Similarity

71%

OpenAI: GPT-5.6 Sol uses 3.3x more emoji

GPT-5.1-Codex

OpenAI: GPT-5.6 Sol

70%Vocabulary63%

17wSentence Length15w

0.39Hedging0.79

3.4Bold3.4

3.5Lists3.8

0.00Emoji0.03

0.50Headings0.95

0.38Transitions0.08

Based on 14 + 27 text responses

Research

What we learned reading every model

GPT-5.1-Codex and OpenAI: GPT-5.6 Sol 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-5.1-Codex vs MiniMax M3New provider

GPT-5.1-Codex vs Claude Opus 4.1New provider

GPT-5.1-Codex vs GPT-5Same lab

Updated Jul 2026

Our Verdict

OpenAI: GPT-5.6 Sol

GPT-5.1-CodexRunner-up

No community votes yet. On paper, OpenAI: GPT-5.6 Sol has the edge — newer, bigger context window.

GPT-5.1-Codex is 3.0x cheaper per token — worth considering if cost matters.

Too close to call

API pricing

Cost per 1M tokens

GPT-5.1-Codex

Input

$1.25

4.0× cheaper

Output

$10.00

3.0× cheaper

OpenAI: GPT-5.6 Sol

Input

$5.00

Output

$30.00

GPT-5.1-Codex is cheaper on both — 4.0× input, 3.0× output

Writing DNA

Style Comparison

Similarity

71%

OpenAI: GPT-5.6 Sol uses 3.3x more emoji

GPT-5.1-Codex

OpenAI: GPT-5.6 Sol

70%Vocabulary63%

17wSentence Length15w

0.39Hedging0.79

3.4Bold3.4

3.5Lists3.8

0.00Emoji0.03

0.50Headings0.95

0.38Transitions0.08

Based on 14 + 27 text responses

Research

What we learned reading every model

GPT-5.1-Codex and OpenAI: GPT-5.6 Sol 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-5.1-Codex vs MiniMax M3New provider

GPT-5.1-Codex vs Claude Opus 4.1New provider

GPT-5.1-Codex vs GPT-5Same lab