What is the difference between GPT-5.5 and OpenAI o4-mini?

Both are developed by OpenAI but target different use cases. You can compare their actual outputs across 53 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.5 or OpenAI o4-mini?

It depends on your use case. GPT-5.5 and OpenAI o4-mini 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 GPT-5.5 cost compared to OpenAI o4-mini?

GPT-5.5 costs $5/M input tokens and OpenAI o4-mini costs $1.1/M input tokens. OpenAI o4-mini is $3.90/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-5.5 and OpenAI o4-mini on Rival?

This page shows a side-by-side comparison of GPT-5.5 and OpenAI o4-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.

Updated Apr 2026

GPT-5.5vsOpenAI o4-mini

OpenAI o4-mini is cheaper than GPT-5.5 at $1.1/M vs $5/M input tokens.

GPT-5.5 and OpenAI o4-mini compared across 53 shared prompts
Spec	GPT-5.5	OpenAI o4-mini
Input price	$5/M tokens	$1.1/M tokens
Output price	$30/M tokens	$4.4/M tokens
Context window	1.1M tokens	—
Weights	Closed	Closed
Free API (OpenRouter)	No	No
Released	Apr 2026	Apr 2025