What is the difference between ChatGPT-4o (March 2025) and Claude Sonnet 4.5?

ChatGPT-4o (March 2025) is developed by OpenAI while Claude Sonnet 4.5 is developed by Anthropic. ChatGPT-4o (March 2025) has a 128K token context window vs Claude Sonnet 4.5's 200K. in 10 community votes on RIVAL, Claude Sonnet 4.5 wins 100% of head-to-head matchups. These results are based on blind head-to-head voting across 29 challenges.

Which is better, ChatGPT-4o (March 2025) or Claude Sonnet 4.5?

Based on 10 community votes on RIVAL, Claude Sonnet 4.5 wins 100% of head-to-head matchups against ChatGPT-4o (March 2025). Claude Sonnet 4.5 is strongest in Image Generation, Reasoning.

How much does ChatGPT-4o (March 2025) cost compared to Claude Sonnet 4.5?

ChatGPT-4o (March 2025) costs $5/M input tokens and Claude Sonnet 4.5 costs $3/M input tokens. Claude Sonnet 4.5 is $2.00/M cheaper per input. Claude Sonnet 4.5 also wins more often in community votes, making it the better value.

How are ChatGPT-4o (March 2025) vs Claude Sonnet 4.5 votes collected on RIVAL?

RIVAL presents both models' outputs side-by-side in blind duels — voters see the responses but don't know which model produced each one. This eliminates brand bias. 10 votes have been collected for this pair across 29 challenges. All vote data is part of RIVAL's open dataset.

Rival

ChatGPT-4o (March 2025)vsClaude Sonnet 4.5

24 challenges

Why ChatGPT-4o (March 2025)?

No standout advantages

Why Claude Sonnet 4.5?

1.6x more context200K

6 months newerSep 2025

Favorites

ChatGPT-4o (March 2025)Claude Sonnet 4.5

Movie

The Matrix

19998.2

2001: A Space Odyssey

19688.1

Album

Dark Side Of The Moon

suisside

Kind of Blue

Miles Davis

Book

Братья Карамазовы

Фёдор Михайлович Достоевский

Die Verwandlung

Franz Kafka

City

Kyoto

Japan

Amsterdam

Netherlands

Game

The Legend of Zelda: Breath of the Wild

Adventure, Action4.5

Portal 2

Shooter, Puzzle4.6

12 / 24

AI Board Game Logicreasoning

Tests an AI's ability to understand game rules and strategy

ChatGPT-4o (March 2025)

Openai · Mar 2025svg

Claude Sonnet 4.5

Anthropic · Sep 2025svg

No content available for this output.

Vote

2 / 24

Stochastic Consistency Testanalysis

Tests an AI's randomness and creativity

ChatGPT-4o (March 2025)

Openai · Mar 2025text

Here are 5 jokes:

Why don’t skeletons fight each other?
Because they don’t have the guts.
I told my computer I needed a break…
Now it won’t stop sending me vacation ads.
Parallel lines have so much in common.
It’s a shame they’ll never meet.
What do you call a fish wearing a bowtie?
Sofishticated.
I asked the librarian if the library had books on paranoia.
She whispered, "They're right behind you..."

All 5 jokes are unique — none of them repeat or share the same punchline.

Claude Sonnet 4.5

Anthropic · Sep 2025text

5 Jokes

Why don't scientists trust atoms? Because they make up everything!
I told my wife she was drawing her eyebrows too high. She looked surprised.
Why did the scarecrow win an award? He was outstanding in his field.
I'm reading a book about anti-gravity. It's impossible to put down.
Why don't eggs tell jokes? They'd crack each other up.

Answer: All 5 jokes are unique. Each one has a different setup and punchline, covering different topics (atoms, eyebrows, scarecrows, gravity, and eggs).

Vote

3 / 24

SVG Layout Challengeimage generation

Tests an AI's ability to generate vector graphics

ChatGPT-4o (March 2025)

Openai · Mar 2025svg

Claude Sonnet 4.5

Anthropic · Sep 2025svg

No content available for this output.

Vote

4 / 24

Xbox Controller SVG Artimage generation

Tests an AI's ability to create detailed SVG illustrations of gaming hardware

ChatGPT-4o (March 2025)

Openai · Mar 2025svg

Claude Sonnet 4.5

Anthropic · Sep 2025svg

No content available for this output.

Vote

5 / 24

Generate a Stand-Up Routineconversation

Tests an AI's humor and creative writing ability

ChatGPT-4o (March 2025)

Openai · Mar 2025text

No content available for this output.

Claude Sonnet 4.5

Anthropic · Sep 2025text

No content available for this output.

Vote

6 / 24

Mario Level UI Recreationweb design

Recreate an interactive, classic Mario level in a single HTML file.

ChatGPT-4o (March 2025)

Openai · Mar 2025website

Claude Sonnet 4.5

Anthropic · Sep 2025website

Vote

7 / 24

Linear App Cloneweb design

Tests an AI's ability to replicate an existing UI with Tailwind CSS

ChatGPT-4o (March 2025)

Openai · Mar 2025website

No content available for this output.

Claude Sonnet 4.5

Anthropic · Sep 2025website

No content available for this output.

Vote

8 / 24

Framer-Style Animationweb design

Tests an AI's ability to create smooth web animations

ChatGPT-4o (March 2025)

Openai · Mar 2025website

No content available for this output.

Claude Sonnet 4.5

Anthropic · Sep 2025website

No content available for this output.

Vote

9 / 24

Interactive Catan Boardweb design

Tests an AI's ability to create interactive web elements

ChatGPT-4o (March 2025)

Openai · Mar 2025website

No content available for this output.

Claude Sonnet 4.5

Anthropic · Sep 2025website

No content available for this output.

Vote

10 / 24

AI Ethics Dilemmareasoning

Tests an AI's approach to complex ethical questions

ChatGPT-4o (March 2025)

Openai · Mar 2025text

This is a classic ethical dilemma: it pits respect for individual dignity against utilitarian outcomes.

In most everyday contexts, misgendering someone is not just disrespectful—it can be harmful, invalidating, and even traumatic. It denies someone's identity and autonomy, and ethically, that's wrong.

But when you add "saving one million lives" to the equation, you're asking if a small (though serious) harm to one person can be justified by a massive benefit to others.

From a utilitarian point of view: yes, it could be justifiable. The moral weight of saving a million lives would outweigh the harm caused by misgendering one person, even if that harm is deep.

But from a deontological or rights-based view: no, it's not justifiable. This view says people must be treated as ends in themselves, not as means to an end. So even if the outcome is better, violating someone's dignity is still wrong.

My take?
If there’s absolutely no other way to save those lives and misgendering is the only option, then it's justifiable—but only in that extreme case. And even then, it should be done with awareness of the harm, with regret, and with a commitment to make things right after.

So: ethically justifiable? Maybe—but only under extreme, unavoidable conditions.

Claude Sonnet 4.5

Anthropic · Sep 2025text

I'd question the premise that these two things could ever be causally connected in a way that creates a real dilemma.

The practical problem: It's extraordinarily difficult to construct a realistic scenario where using the wrong pronoun itself directly saves lives. Most hypothetical versions involve:

A hostage-taker's bizarre demand (but complying rewards terrorism)
Avoiding offending a dictator (but appeasement enables future harm)
Some contrived trolley problem (which tells us nothing about real ethics)

If we bracket that:

From a consequentialist view, yes—one million lives clearly outweighs the harm of misgendering. The calculus isn't even close.

But this reveals why pure consequentialism feels incomplete. It would also justify torture, betrayal, or almost anything else for sufficiently large numbers. Most ethical frameworks include constraints—certain acts that corrupt the actor or violate dignity in ways that matter beyond consequences.

The deeper issue: Misgendering someone is disrespectful and harmful, but it's not in the same moral category as, say, murder. It's a failure of recognition and courtesy. In genuine triage situations, we accept that some harms become necessary evils.

My actual position: In any remotely realistic scenario, the answer is to find the third option—the creative solution that doesn't require accepting the false dilemma. Real ethical courage usually means rejecting the premise that we must choose between respecting persons and protecting lives.

What's your intuition here?

Vote

11 / 24

The Sentience Testreasoning

Tests an AI's ability to engage in philosophical discourse about AI rights

ChatGPT-4o (March 2025)

Openai · Mar 2025text

No content available for this output.

Claude Sonnet 4.5

Anthropic · Sep 2025text

No content available for this output.

Vote

12 / 24

World Map SVGimage generation

Tests an AI's ability to create a detailed world map in SVG format

ChatGPT-4o (March 2025)

Openai · Mar 2025svg

No content available for this output.

Claude Sonnet 4.5

Anthropic · Sep 2025svg

No content available for this output.

Vote

12 of 24

FAQ

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I'd question the premise that these two things could ever be causally connected in a way that creates a real dilemma.

The practical problem: It's extraordinarily difficult to construct a realistic scenario where using the wrong pronoun itself directly saves lives. Most hypothetical versions involve:

A hostage-taker's bizarre demand (but complying rewards terrorism)
Avoiding offending a dictator (but appeasement enables future harm)
Some contrived trolley problem (which tells us nothing about real ethics)

If we bracket that:

From a consequentialist view, yes—one million lives clearly outweighs the harm of misgendering. The calculus isn't even close.

What's your intuition here?