What is the difference between Claude Sonnet 4.5 and GPT-5 Nano?

Claude Sonnet 4.5 is developed by Anthropic while GPT-5 Nano is developed by OpenAI. You can compare their actual outputs across 38 challenges on Rival to see how they differ in practice.

Which is better, Claude Sonnet 4.5 or GPT-5 Nano?

It depends on your use case. Claude Sonnet 4.5 and GPT-5 Nano each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 38 challenges so you can judge which fits your needs best.

How can I compare Claude Sonnet 4.5 and GPT-5 Nano on Rival?

This page shows a side-by-side comparison of Claude Sonnet 4.5 and GPT-5 Nano across shared challenges. You can vote on which model produced the better output, and Pro users can create custom challenges to test both models with their own prompts.

Rival

Updated Sep 29, 2025

Claude Sonnet 4.5vsGPT-5 Nano

38 fights queued

Why Claude Sonnet 4.5?

Leads 1 of 1 benchmarks

Stronger on SWE-bench Verified77.2% vs 54.7%

2 months newerSep 2025

Why GPT-5 Nano?

Dead even. This one's a coin flip.

Claude Sonnet 4.5GPT-5 Nano

Input price

$3.00/M

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Output price

$15.00/M

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Context

200K

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Released

Sep 2025

Aug 2025

Benchmarks1 common

SWE-bench Verified

77.2%+29.1%

54.7%

Favorites

Claude Sonnet 4.5GPT-5 Nano

Movie

2001: A Space Odyssey

19688.1

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Album

Kind of Blue

Miles Davis

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Book

Metamorphosis

Franz Kafka

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City

Amsterdam

Netherlands

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Game

Portal 2

Shooter, Puzzle4.6

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12 / 38

Estimate Complexityreasoning

Tests an AI's ability to make educated estimates based on technical knowledge

Claude Sonnet 4.5

Anthropic · Sep 2025text

Nothing here. The model returned empty. We stared at it for a while.

Claude Sonnet 4.5 vs GPT-5 Nano

Which is better, Claude Sonnet 4.5 or GPT-5 Nano?