The issue is that Safari pops up JavaScript alerts as a native dialog box, which can’t be ignored until it’s dismissed (since it stops you from doing anything e

The issue is that Safari pops up JavaScript alerts as a native dialog box, which can’t be ignored until it’s dismissed (since it stops you from doing anything else). A nice extension you can use for Safari that replaces the native dialog boxes for JavaScript alerts with an HTML one that’s in the page itself is JS Blocker¹. It can do much, much more than that though, but if that’s the only thing you want it to do, then just make sure that only 'Display alert messages within the webpage instead of a popup dialog' is checked² in Settings → Other → Extra Features. It should look like this³ when you’re on a webpage. ―――――― ¹ — http://jsblocker.toggleable.com http://jsblocker.toggleable.com ² — http://f.cl.ly/items/0f2o110o3V1A1w1z2p0p/jsalerts.png http://f.cl.ly/items/0f2o110o3V1A1w1z2p0p/jsalerts.png ³ — http://f.cl.ly/items/3g242r322C443G0j1O3J/jsalerts2.png http://f.cl.ly/items/3g242r322C443G0j1O3J/jsalerts2.png