⬇️ Just drag the "mainonly" button to your bookmarks bar.

• Click the bookmarklet to activate.
• Select the element to focus. This selected element will be encircled with a red outline. Use the scroll wheel or keyboard shortcut (- , for expand, = . for shrink) to adjust the selection size.
• Once you've made a selection, click the left mouse button. All other elements will be hidden, leaving only the selected element visible.
• Press ESC to reveal the hidden elements and revert the page to its original state.

Try using the bookmarklet on this page to see how it works.

Found this useful? Or just interested in how it works? Check out the Github repo for more. (Or just add a star)