What is the difference between OpenAI Codex Mini and Gemini 3.8 Flash?

OpenAI Codex Mini is developed by OpenAI while Gemini 3.8 Flash is developed by Google AI. OpenAI Codex Mini has a 200K token context window vs Gemini 3.8 Flash's 1.0M. You can compare their actual outputs across 10 challenges on Rival to see how they differ in practice.

Which is better, OpenAI Codex Mini or Gemini 3.8 Flash?

It depends on your use case. OpenAI Codex Mini and Gemini 3.8 Flash each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 10 challenges so you can judge which fits your needs best.

How much does OpenAI Codex Mini cost compared to Gemini 3.8 Flash?

OpenAI Codex Mini costs $1.5/M input tokens and Gemini 3.8 Flash costs $0.75/M input tokens. Gemini 3.8 Flash is $0.75/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 OpenAI Codex Mini and Gemini 3.8 Flash on Rival?

This page shows a side-by-side comparison of OpenAI Codex Mini and Gemini 3.8 Flash 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 Sep 2026

OpenAI Codex MinivsGemini 3.8 Flash

Gemini 3.8 Flash is cheaper than OpenAI Codex Mini at $0.75/M vs $1.5/M input tokens.

OpenAI Codex Mini and Gemini 3.8 Flash compared across 10 shared prompts
Spec	OpenAI Codex Mini	Gemini 3.8 Flash
Input price	$1.5/M tokens	$0.75/M tokens
Output price	$6/M tokens	$3.75/M tokens
Context window	200K tokens	1.0M tokens
Weights	—	Closed
Free API (OpenRouter)	No	No
Released	May 2025	Sep 2026