# Anthropic said it cut 80% of the system prompt for Opus 5

*Published on: Sat, 25 Jul 2026 17:22:06 GMT*

Anthropic said it cut 80% of the system prompt for Opus 5

I checked the claim:
Opus 4.8: 130K characters
Opus 5: 135K characters

So the prompt actually got longer. Maybe they meant some specific section inside the system prompt. Or maybe not.

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