Auto Reload refreshes Safari windows with repeating timers. Just dial in an interval between one second and one hour then press start to begin reloading automatically. As a native Mac App extension, it is fast, efficient, and safe. No scripts are injected into pages and no extra permissions to view browsing history or webpage contents is required (or asked for).
After installing from the App Store, open Auto Reload to add the extension to Safari. Enable or disable the toolbar item in Safari preferences. Drag the application too Trash to completely uninstall the extension. Be advised that rapidly reloading web pages comes with performance and energy costs; and may annoy webmasters. Please use responsibly.