What is the difference between GPT-5.1 and Horizon Alpha?

GPT-5.1 is developed by OpenAI while Horizon Alpha is developed by OpenRouter. GPT-5.1 has a 400K token context window vs Horizon Alpha's 256K. You can compare their actual outputs across 33 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.1 or Horizon Alpha?

It depends on your use case. GPT-5.1 and Horizon Alpha each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 33 challenges so you can judge which fits your needs best.

How much does GPT-5.1 cost compared to Horizon Alpha?

GPT-5.1 costs $1.25/M input tokens and Horizon Alpha costs $0/M input tokens. Horizon Alpha is $1.25/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-5.1 and Horizon Alpha on Rival?

This page shows a side-by-side comparison of GPT-5.1 and Horizon Alpha 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.

What is the difference between GPT-5.1 and Horizon Alpha?

GPT-5.1 is developed by OpenAI while Horizon Alpha is developed by OpenRouter. GPT-5.1 has a 400K token context window vs Horizon Alpha's 256K. You can compare their actual outputs across 33 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.1 or Horizon Alpha?

It depends on your use case. GPT-5.1 and Horizon Alpha each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 33 challenges so you can judge which fits your needs best.

How much does GPT-5.1 cost compared to Horizon Alpha?

GPT-5.1 costs $1.25/M input tokens and Horizon Alpha costs $0/M input tokens. Horizon Alpha is $1.25/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-5.1 and Horizon Alpha on Rival?

This page shows a side-by-side comparison of GPT-5.1 and Horizon Alpha 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.