Is there a 30 percent rule for AI content in SEO?

No, there is no real 30 percent rule. It is a popular myth that circulates around SEO forums, sometimes cited as 30 percent, sometimes as a 70/30 split or a 20/60/20 split, but Google has never published any such specific threshold anywhere.

Google's actual public stance is about quality and intent, not the authorship method used. Its own guidance says content made primarily to game rankings gets penalized, whether a person or a model wrote the original draft.

The safer rule of thumb is not a percentage at all, it is whether a human reviewed and genuinely improved the draft enough that it reads as actually useful, not just AI text left completely untouched.

That review-and-improve step is exactly what a de-AI pass inside automatic SEO software is built to handle.