What is the difference between Claude Sonnet 4.5 and GPT-6 Astra Pro?

Claude Sonnet 4.5 is developed by Anthropic while GPT-6 Astra Pro is developed by OpenAI. Claude Sonnet 4.5 has a 200K token context window vs GPT-6 Astra Pro's 1.1M. You can compare their actual outputs across 4 challenges on Rival to see how they differ in practice.

Which is better, Claude Sonnet 4.5 or GPT-6 Astra Pro?

It depends on your use case. Claude Sonnet 4.5 and GPT-6 Astra Pro each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 4 challenges so you can judge which fits your needs best.

How much does Claude Sonnet 4.5 cost compared to GPT-6 Astra Pro?

Claude Sonnet 4.5 costs $3/M input tokens and GPT-6 Astra Pro costs $10/M input tokens. Claude Sonnet 4.5 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 Claude Sonnet 4.5 and GPT-6 Astra Pro on Rival?

This page shows a side-by-side comparison of Claude Sonnet 4.5 and GPT-6 Astra Pro 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

Claude Sonnet 4.5vsGPT-6 Astra Pro

Claude Sonnet 4.5 is cheaper than GPT-6 Astra Pro at $3/M vs $10/M input tokens.

Claude Sonnet 4.5 and GPT-6 Astra Pro compared across 4 shared prompts
Spec	Claude Sonnet 4.5	GPT-6 Astra Pro
Input price	$3/M tokens	$10/M tokens
Output price	$15/M tokens	$50/M tokens
Context window	200K tokens	1.1M tokens
Weights	Closed	Closed
Free API (OpenRouter)	No	No
Released	Sep 2025	Sep 2026