noindex and robots disallow are not interchangeable, and people keep swapping them

noindex and robots disallow are not interchangeable, and people keep swapping them

Myth: both "get rid of" a page, so pick whichever.

No. They solve opposite problems.

robots disallow blocks the crawl — Google never fetches the page, so it never sees your noindex tag. The URL can still rank as a naked link with zero content. You've hidden the gun and kept the trigger.

noindex requires a crawl. Google must fetch the page to read the directive, drop it from the index, then keep checking it periodically. That costs crawl, by design.

The tradeoff that actually matters: disallow to save crawl on junk Google hasn't indexed yet. noindex to remove junk that's already indexed — then disallow later once it's gone.

Use the wrong one and you lock the door on a page Google can't read.