To mark all emails as read in Gmail, follow these steps using the desktop web version:

1. Open Gmail in your browser and log in.
2. In the search bar at the top, type is:unread and press Enter. This filters to show all unread emails.
3. Click the checkbox at the top left to select all emails on the current page.
4. A message will appear near the top saying “Select all conversations that match this search.” Click this link to select every unread email in your account.
5. Click the “Mark as read” button (usually found as an envelope icon or under the three-dot menu).
6. Confirm if prompted. Gmail will then mark all selected emails as read. This process may take a few moments if you have many unread emails

Note that the Gmail mobile app does not support marking all emails as read at once, so this method requires a desktop browser

. If you want to automate marking future emails as read, you can create a Gmail filter that automatically marks incoming messages as read

. This method efficiently clears your unread email count and helps manage a cluttered inbox.