What is the difference between GPT-5 Pro and Grok 4.20 Beta?

GPT-5 Pro is developed by OpenAI while Grok 4.20 Beta is developed by xAI. GPT-5 Pro has a 400K token context window vs Grok 4.20 Beta's 2.0M. You can compare their actual outputs across 41 challenges on Rival to see how they differ in practice.

Which is better, GPT-5 Pro or Grok 4.20 Beta?

It depends on your use case. GPT-5 Pro and Grok 4.20 Beta each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 41 challenges so you can judge which fits your needs best.

How much does GPT-5 Pro cost compared to Grok 4.20 Beta?

GPT-5 Pro costs $15/M input tokens and Grok 4.20 Beta costs $2/M input tokens. Grok 4.20 Beta is $13.00/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 Pro and Grok 4.20 Beta on Rival?

This page shows a side-by-side comparison of GPT-5 Pro and Grok 4.20 Beta 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 Mar 2026

GPT-5 ProvsGrok 4.20 Beta

Grok 4.20 Beta is cheaper than GPT-5 Pro at $2/M vs $15/M input tokens.

GPT-5 Pro and Grok 4.20 Beta compared across 41 shared prompts
Spec	GPT-5 Pro	Grok 4.20 Beta
Input price	$15/M tokens	$2/M tokens
Output price	$120/M tokens	$6/M tokens
Context window	400K tokens	2.0M tokens
Weights	Closed	Closed
Free API (OpenRouter)	No	No
Released	Oct 2025	Mar 2026