Simon Willison diffs Claude Opus 4.6 vs 4.7 system prompts
@simonwillison.net posted a Bluesky note linking to his analysis of the differences between Claude Opus 4.6 and 4.7 system prompts, made possible because Anthropic publishes their system prompts publicly.
Score breakdown
Practitioners tracking Claude model behavior can use Anthropic's published system prompts to diff versions and understand how model instructions evolve between releases.
- 01@simonwillison.net posted about diffing Claude Opus 4.6 and 4.7 system prompts on Bluesky.
- 02The analysis is possible because Anthropic publicly publishes their system prompts.
- 03The full notes are published at simonwillison.net/2026/Apr/18/opus-system-prompt/.
@simonwillison.net shared a Bluesky post linking to his notes on what changed between the Claude Opus 4.6 and 4.7 system prompts. The analysis was made possible because Anthropic publicly publishes their system prompts, allowing a diff to be generated between versions. The full write-up is available at simonwillison.net.
Key facts
- 01@simonwillison.net posted about diffing Claude Opus 4.6 and 4.7 system prompts on Bluesky.
- 02The analysis is possible because Anthropic publicly publishes their system prompts.
- 03The full notes are published at simonwillison.net/2026/Apr/18/opus-system-prompt/.
- 04The post was published on 2026-04-19.
Topics
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