What is the difference between GPT-4.5 and Horizon Alpha?

GPT-4.5 is developed by OpenAI while Horizon Alpha is developed by OpenRouter. GPT-4.5 has a 128K token context window vs Horizon Alpha's 256K. You can compare their actual outputs across 22 challenges on Rival to see how they differ in practice.

Which is better, GPT-4.5 or Horizon Alpha?

It depends on your use case. GPT-4.5 and Horizon Alpha each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 22 challenges so you can judge which fits your needs best.

How much does GPT-4.5 cost compared to Horizon Alpha?

GPT-4.5 costs $75/M input tokens and Horizon Alpha costs $0/M input tokens. Horizon Alpha is $75.00/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-4.5 and Horizon Alpha on Rival?

This page shows a side-by-side comparison of GPT-4.5 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-4.5 and Horizon Alpha?

GPT-4.5 is developed by OpenAI while Horizon Alpha is developed by OpenRouter. GPT-4.5 has a 128K token context window vs Horizon Alpha's 256K. You can compare their actual outputs across 22 challenges on Rival to see how they differ in practice.

Which is better, GPT-4.5 or Horizon Alpha?

It depends on your use case. GPT-4.5 and Horizon Alpha each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 22 challenges so you can judge which fits your needs best.

How much does GPT-4.5 cost compared to Horizon Alpha?

GPT-4.5 costs $75/M input tokens and Horizon Alpha costs $0/M input tokens. Horizon Alpha is $75.00/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-4.5 and Horizon Alpha on Rival?

This page shows a side-by-side comparison of GPT-4.5 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.

GPT-4.5 vs Horizon Alpha: Which Is Better?

Updated Jul 2025

Our Verdict

GPT-4.5

Horizon Alpha

No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.

Too close to call

API pricing

Cost per 1M tokens

GPT-4.5

Input

$75.00

Output

$150.00

Horizon Alpha

Input

$0.000

Output

$0.000

Writing DNA

Style Comparison

Similarity

55%

GPT-4.5 uses 466.6x more bold

GPT-4.5

Horizon Alpha

63%Vocabulary65%

16wSentence Length14w

0.57Hedging0.22

4.7Bold0.0

6.4Lists3.5

0.00Emoji0.00

1.30Headings0.00

0.54Transitions0.12

Based on 11 + 14 text responses

Research

What we learned reading every model

GPT-4.5 and Horizon Alpha have opinions about your brand too.Ask 10 models what they tell people about you. Verbatim receipts.Run the mirror

FAQ

Common questions

Keep exploring

More comparisons

GPT-4.5 vs MiniMax M3New provider

GPT-4.5 vs Llama 4 MaverickNew provider

Horizon Alpha vs GPT-5Cross-provider

Updated Jul 2025

Our Verdict

GPT-4.5

Horizon Alpha

No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.

Too close to call

API pricing

Cost per 1M tokens

GPT-4.5

Input

$75.00

Output

$150.00

Horizon Alpha

Input

$0.000

Output

$0.000

Writing DNA

Style Comparison

Similarity

55%

GPT-4.5 uses 466.6x more bold

GPT-4.5

Horizon Alpha

63%Vocabulary65%

16wSentence Length14w

0.57Hedging0.22

4.7Bold0.0

6.4Lists3.5

0.00Emoji0.00

1.30Headings0.00

0.54Transitions0.12

Based on 11 + 14 text responses

Research

What we learned reading every model

GPT-4.5 and Horizon Alpha have opinions about your brand too.Ask 10 models what they tell people about you. Verbatim receipts.Run the mirror

FAQ

Common questions

Keep exploring

More comparisons

GPT-4.5 vs MiniMax M3New provider

GPT-4.5 vs Llama 4 MaverickNew provider

Horizon Alpha vs GPT-5Cross-provider