What is the difference between GPT-5 Codex and Inkling?

GPT-5 Codex is developed by OpenAI while Inkling is developed by Thinking Machines. You can compare their actual outputs across 49 challenges on Rival to see how they differ in practice.

Which is better, GPT-5 Codex or Inkling?

It depends on your use case. GPT-5 Codex and Inkling each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 49 challenges so you can judge which fits your needs best.

How can I compare GPT-5 Codex and Inkling on Rival?

This page shows a side-by-side comparison of GPT-5 Codex and Inkling 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 Jul 2026

GPT-5 CodexvsInkling

Inkling is the newer model, released after GPT-5 Codex.

GPT-5 Codex and Inkling compared across 49 shared prompts
Spec	GPT-5 Codex	Inkling
Input price	—	$1/M tokens
Output price	—	$4.05/M tokens
Context window	—	1.0M tokens
Weights	—	Open
Free API (OpenRouter)	No	Yes (1 provider)
Released	Sep 2025	Jul 2026