What is the difference between GPT-6 Astra Pro and Grok 4?

GPT-6 Astra Pro is developed by OpenAI while Grok 4 is developed by xAI. GPT-6 Astra Pro has a 1.1M token context window vs Grok 4's 256K. You can compare their actual outputs across 6 challenges on Rival to see how they differ in practice.

Which is better, GPT-6 Astra Pro or Grok 4?

It depends on your use case. GPT-6 Astra Pro and Grok 4 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 6 challenges so you can judge which fits your needs best.

How much does GPT-6 Astra Pro cost compared to Grok 4?

GPT-6 Astra Pro costs $10/M input tokens and Grok 4 costs $3/M input tokens. Grok 4 is $7.00/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-6 Astra Pro and Grok 4 on Rival?

This page shows a side-by-side comparison of GPT-6 Astra Pro and Grok 4 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

GPT-6 Astra ProvsGrok 4

Grok 4 is cheaper than GPT-6 Astra Pro at $3/M vs $10/M input tokens.

GPT-6 Astra Pro and Grok 4 compared across 6 shared prompts
Spec	GPT-6 Astra Pro	Grok 4
Input price	$10/M tokens	$3/M tokens
Output price	$50/M tokens	$15/M tokens
Context window	1.1M tokens	256K tokens
Weights	Closed	—
Free API (OpenRouter)	No	No
Released	Sep 2026	Jul 2025

Our Verdict

GPT-6 Astra Pro

Grok 4Runner-up

Not enough votes to call it. On the specs, GPT-6 Astra Pro has the edge: bigger model tier, newer, bigger context window.

Grok 4 costs 3.3x less per token.

Slight edge

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

GPT-6 Astra Pro

Input

$10.00

Output

$50.00

Grok 4

Input

$3.00

3.3× cheaper

Output

$15.00

3.3× cheaper

Grok 4 is cheaper on both: 3.3× input, 3.3× output.

Where to run it

2 hosts

GPT-6 Astra Pro2 hosts

HostInOutContextUptime

Azure AI Foundry$10.00 in$50.00 out1.1M98.9% up OpenAI$10.00 in$50.00 out1.1M99.6% up

Grok 4

No hosts listed on OpenRouter.

Per million tokens. Prices and uptime via OpenRouter, checked 16 Sep 2026.

Research

What we learned reading every model

FAQ

Common questions

Keep exploring

More comparisons

Cost per 1M tokens

2 hosts

What we learned reading every model

Common questions

What is the difference between GPT-6 Astra Pro and Grok 4?

Which is better, GPT-6 Astra Pro or Grok 4?

How much does GPT-6 Astra Pro cost compared to Grok 4?

How can I compare GPT-6 Astra Pro and Grok 4 on Rival?

More comparisons

Against the newest arrivals

Same lab, same size, long tail

Model pages

Cost per 1M tokens

2 hosts

What we learned reading every model

Common questions

What is the difference between GPT-6 Astra Pro and Grok 4?

Which is better, GPT-6 Astra Pro or Grok 4?

How much does GPT-6 Astra Pro cost compared to Grok 4?

How can I compare GPT-6 Astra Pro and Grok 4 on Rival?

More comparisons

Against the newest arrivals

Same lab, same size, long tail

Model pages