Mark All Unread Messages as Read in Gmail

If you’ve got an overstuffed inbox and you want to declare Inbox Zero without individually marking messages as read, you can mark all unread mail as read using a Gmail filter. Create a new filter with is:unread in the Has the words field, then tell Gmail to Mark as read all matching messages. Finally, tick the box next to Also apply filter to conversations below and create the filter. The filter will mark all your unread items as read. If you just want to clear out unread items in a specific label, add something like label:Followup to the Has the words box with is:unread. Simple, quick, and you don’t have to page through thousands of emails to get the job done. Just be sure to delete the filter when you’re done. UPDATE: As bostonguy points out, Gmail has added an option in search results to select all conversations that match a search, which makes the filter unnecessary. See the screenshot after the jump.

As you can see, you can either select the visible matches of a search or select every single conversation in Gmail that matches a search. That means you can easily mark all email as unread by label, date, or whatever, without creating a filter. Thanks bostonguy!