As far as I know, Firefox doesn’t currently have a built-in setting to permanently change the default sort order for file:// directory listings. It pretty much always falls back to sorting by name when opening local folders directly in the browser. You can manually click “Last Modified” each time, but I don’t think there’s an about:config option for making it persistent globally. for log folders specifically, a lot of people end up using either: a dedicated file manager window alongside Firefox a small local web server or extensions/userscripts that customize directory listings Feels like one of those tiny quality-of-life things Firefox surprisingly still doesn’t expose as a setting.