-Access the DevTools panel by pressing the F12 key -Click the vertical Ellipsis icon — three dots — to the upper-right corner of the DevTools panel. On the drop-down menu, select Settings -Click the Throttling side-tab. You should now be on the Network Throttling Profiles screen. To start creating a custom profile, click the Add Custom Profile button -and go to the tab you want to apply the throttling, to the tab Network, select from the combo the new profile you have created.
https://www.guidingtech.com/manage-throttle-download-speed-chrome/
origin - https://www.pipiscrew.com/?p=17489 limit-bandwidth-for-each-tab-in-chrome