browserconfig.xml and Windows Tile Icons
browserconfig.xml told Internet Explorer and legacy Edge which images and colour to use for a pinned-site tile on the Windows Start menu, alongside the msapplication-TileColor and msapplication-TileImage meta tags. Modern Windows and Chromium Edge no longer read it, so it's safe to drop from new sites, though generators still emit it for backward compatibility.
Pinned tiles for the Windows Start menu
When you pinned a site to the Start menu in Internet Explorer or the original Edge, Windows drew a coloured tile using dedicated images. browserconfig.xml, placed at the site root, listed those tile images at their sizes (70, 150, 310 pixels), and the msapplication-TileColor meta tag set the tile's background colour.
Chromium-based Edge and modern Windows dropped this system in favour of the web app manifest, which now supplies install icons and theme colour. So browserconfig.xml and the msapplication tags are legacy: present in many generated icon sets, read by almost nothing.
A browserconfig.xml file
<?xml version="1.0" encoding="utf-8"?>
<browserconfig>
<msapplication>
<tile>
<square150x150logo src="/mstile-150x150.png" />
<TileColor>#111111</TileColor>
</tile>
</msapplication>
</browserconfig>Referenced from the head with <meta name="msapplication-config" content="/browserconfig.xml" />.
Windows tile FAQ
Do I need browserconfig.xml?
Not for any modern browser. It only affected pinned-site tiles in Internet Explorer and legacy Edge. The web app manifest handles install icons today.
What is msapplication-TileImage?
A meta tag that pointed old Windows at the image to use for a pinned-site tile, with msapplication-TileColor setting the tile's background. Both are legacy Microsoft-specific tags.
Can I delete browserconfig.xml?
Yes, unless you specifically support pinned tiles on old Windows. Removing it and the msapplication meta tags has no effect on any current browser.