Content ages, and stale content harms.
THE PROBLEM
Pages that were accurate three years ago and are now wrong damage trust and rank poorly. Readers who find outdated advice do not return.
FINDING IT
Review anything older than two years Check pages with declining traffic Check anything mentioning prices, versions, procedures or dates
THE OPTIONS
Update it, if the topic is still relevant. This is usually best, because the page keeps its accumulated authority. Merge it into a better page, with a redirect. Remove it, with a redirect to the closest relevant page. Leave it, if it remains accurate.
WHAT NOT TO DO
Delete it without a redirect. Anyone following a link or a search result gets a 404.
MARKING UPDATES
Where a page has been substantially revised, saying so is honest and reassures readers that the content is maintained.
A ROUTINE
Review a portion of your content each quarter rather than attempting everything at once.
The pages worth reviewing first are the ones with traffic.