JS favicon frame replacement

Watch this page’s browser tab. JavaScript generates a new, entirely static SVG image and assigns it to the page’s <link rel="icon"> element every 125 milliseconds: eight separate favicon frames per second.

The favicon contains no SVG animation, GIF, APNG, video, or CSS animation. Every frame is an embedded data: URL, so the favicon makes no network requests. If the tab icon appears to spin, the browser is accepting repeated replacements of static images—not playing an animated favicon resource.

On-page reference

This image receives the same static frames. Movement here confirms that the script is running; the browser tab is the actual test.

Method

JavaScript frame replacement

Nominal rate

8 frames per second

Frame format

static SVG in a data: URL

Favicon network requests

none

Replacements so far

0

There are no controls and no alternative test modes. Frame replacement begins automatically when the page loads and continues for as long as the page’s JavaScript is allowed to run.