What is the difference between Claude Opus 4.8 and GPT-4.5?

Claude Opus 4.8 is developed by Anthropic while GPT-4.5 is developed by OpenAI. Claude Opus 4.8 has a 1.0M token context window vs GPT-4.5's 128K. You can compare their actual outputs across 24 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4.8 or GPT-4.5?

It depends on your use case. Claude Opus 4.8 and GPT-4.5 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 24 challenges so you can judge which fits your needs best.

How much does Claude Opus 4.8 cost compared to GPT-4.5?

Claude Opus 4.8 costs $5/M input tokens and GPT-4.5 costs $75/M input tokens. Claude Opus 4.8 is $70.00/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 Claude Opus 4.8 and GPT-4.5 on Rival?

This page shows a side-by-side comparison of Claude Opus 4.8 and GPT-4.5 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 Claude Opus 4.8 and GPT-4.5?

Claude Opus 4.8 is developed by Anthropic while GPT-4.5 is developed by OpenAI. Claude Opus 4.8 has a 1.0M token context window vs GPT-4.5's 128K. You can compare their actual outputs across 24 challenges on Rival to see how they differ in practice.

Which is better, Claude Opus 4.8 or GPT-4.5?

It depends on your use case. Claude Opus 4.8 and GPT-4.5 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 24 challenges so you can judge which fits your needs best.

How much does Claude Opus 4.8 cost compared to GPT-4.5?

Claude Opus 4.8 costs $5/M input tokens and GPT-4.5 costs $75/M input tokens. Claude Opus 4.8 is $70.00/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 Claude Opus 4.8 and GPT-4.5 on Rival?

This page shows a side-by-side comparison of Claude Opus 4.8 and GPT-4.5 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.

Claude Opus 4.8 vs GPT-4.5: Which Is Better?

Updated May 2026

Our Verdict

Claude Opus 4.8

GPT-4.5Runner-up

No community votes yet. On paper, Claude Opus 4.8 has the edge — newer, bigger context window.

Claude Opus 4.8 is 6.0x cheaper per token — worth considering if cost matters.

Too close to call

API pricing

Cost per 1M tokens

Claude Opus 4.8

Input

$5.00

15× cheaper

Output

$25.00

6.0× cheaper

GPT-4.5

Input

$75.00

Output

$150.00

Claude Opus 4.8 is cheaper on both — 15× input, 6.0× output

Writing DNA

Style Comparison

Similarity

31%

Claude Opus 4.8 uses 77.6x more emoji

Claude Opus 4.8

GPT-4.5

60%Vocabulary63%

19wSentence Length16w

0.46Hedging0.57

4.7Bold4.7

3.2Lists6.4

0.78Emoji0.00

1.15Headings1.30

0.04Transitions0.54

Based on 27 + 11 text responses

Research

What we learned reading every model

Claude Opus 4.8 and GPT-4.5 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

Claude Opus 4.8 vs Llama 4 MaverickNew provider

Claude Opus 4.8 vs GPT-5Cross-provider

Updated May 2026

Our Verdict

Claude Opus 4.8

GPT-4.5Runner-up

No community votes yet. On paper, Claude Opus 4.8 has the edge — newer, bigger context window.

Claude Opus 4.8 is 6.0x cheaper per token — worth considering if cost matters.

Too close to call

API pricing

Cost per 1M tokens

Claude Opus 4.8

Input

$5.00

15× cheaper

Output

$25.00

6.0× cheaper

GPT-4.5

Input

$75.00

Output

$150.00

Claude Opus 4.8 is cheaper on both — 15× input, 6.0× output

Writing DNA

Style Comparison

Similarity

31%

Claude Opus 4.8 uses 77.6x more emoji

Claude Opus 4.8

GPT-4.5

60%Vocabulary63%

19wSentence Length16w

0.46Hedging0.57

4.7Bold4.7

3.2Lists6.4

0.78Emoji0.00

1.15Headings1.30

0.04Transitions0.54

Based on 27 + 11 text responses

Research

What we learned reading every model

Claude Opus 4.8 and GPT-4.5 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

Claude Opus 4.8 vs Llama 4 MaverickNew provider

Claude Opus 4.8 vs GPT-5Cross-provider