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

GPT-5.1 is developed by OpenAI while Horizon Beta is developed by OpenRouter. GPT-5.1 has a 400K token context window vs Horizon Beta's 256K. You can compare their actual outputs across 39 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.1 or Horizon Beta?

It depends on your use case. GPT-5.1 and Horizon Beta each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 39 challenges so you can judge which fits your needs best.

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

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

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

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

GPT-5.1 is developed by OpenAI while Horizon Beta is developed by OpenRouter. GPT-5.1 has a 400K token context window vs Horizon Beta's 256K. You can compare their actual outputs across 39 challenges on Rival to see how they differ in practice.

Which is better, GPT-5.1 or Horizon Beta?

It depends on your use case. GPT-5.1 and Horizon Beta each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 39 challenges so you can judge which fits your needs best.

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

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

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

GPT-5.1 vs Horizon Beta: Which Is Better?

Updated Nov 2025

Our Verdict

GPT-5.1

Horizon BetaRunner-up

No community votes yet. On paper, GPT-5.1 has the edge — bigger model tier, newer, bigger context window, major provider backing.

Slight edge

API pricing

Cost per 1M tokens

GPT-5.1

Input

$1.25

Output

$10.00

Horizon Beta

Input

$0.000

Output

$0.000

Writing DNA

Style Comparison

Similarity

50%

GPT-5.1 uses 349.6x more bold

GPT-5.1

Horizon Beta

62%Vocabulary62%

19wSentence Length15w

0.29Hedging0.24

3.5Bold0.0

7.2Lists2.2

0.00Emoji0.00

0.61Headings0.00

0.03Transitions0.18

Based on 14 + 16 text responses

Research

What we learned reading every model

GPT-5.1 and Horizon Beta 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-5.1 vs MiniMax M3New provider

GPT-5.1 vs Grok 3New provider

GPT-5.1 vs Llama 4 MaverickNew provider

Updated Nov 2025

Our Verdict

GPT-5.1

Horizon BetaRunner-up

No community votes yet. On paper, GPT-5.1 has the edge — bigger model tier, newer, bigger context window, major provider backing.

Slight edge

API pricing

Cost per 1M tokens

GPT-5.1

Input

$1.25

Output

$10.00

Horizon Beta

Input

$0.000

Output

$0.000

Writing DNA

Style Comparison

Similarity

50%

GPT-5.1 uses 349.6x more bold

GPT-5.1

Horizon Beta

62%Vocabulary62%

19wSentence Length15w

0.29Hedging0.24

3.5Bold0.0

7.2Lists2.2

0.00Emoji0.00

0.61Headings0.00

0.03Transitions0.18

Based on 14 + 16 text responses

Research

What we learned reading every model

GPT-5.1 and Horizon Beta 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-5.1 vs MiniMax M3New provider

GPT-5.1 vs Grok 3New provider

GPT-5.1 vs Llama 4 MaverickNew provider