robmathers/nopreload

Safari extension to disable preloading of HTML5 audio content.

NoPreload

A Safari extension to prevent webpages from preloading HTML 5 audio content. You can download the latest version from the releases page.

About

NoPreload was created in the spirit of minimizing excess bandwidth usage. As a fan of podcasts, I'm often checking show notes and the like for an episode, only to find that the 40+ MB file starts downloading automatically, when all I wanted was to find a link to something. Unfortunately some sites use audio player libraries that pre-load the audio files, rather than waiting for the user to click play. This extension fixes that — the audio player remains, but it only starts the download once you click play.

Instructions

Download the extension file and open it to install it in Safari. No further configuration is necessary, but if desired, it is possible to set a whitelist or blacklist of sites to control which domains NoPreload runs on. This is accessible from Safari's Extensions Preferences.

If you want to only block preloading on certain domains (whitelisting), select the Only Specified Domains option, and enter the domains you want into the Domain List field. Similarly, if you want to block preloading on all domains except ones you specify (blacklisting), select the All Domains Except Specified option, and enter your blacklisted domains in the Domain List field.

Domains should be separated by commas, with no leading http:// or https://, nor any trailing backslash. Domains will match all subdomains, so example.com will match example.com and www.example.com, whereas www.example.com matches www.example.com but not example.com or blog.example.com.

Technical Details

NoPreload works by setting the preload attribute on any HTML <audio> element to none. It launches after all the initial page load scripts have fired, so it should work with most dynamically inserted players, but not those created on user actions.

Known Issues

• NoPreload only works on players that make use of the HTML <audio> element. This means that it will not block Flash or other plugins, nor is it likely to in the future. For this sort of thing, you should check out the very useful ClickToPlugin extension.

Version History

• 1.0.0: Initial release.
• 1.0.1: Enabled NoPreload for pages served via HTTPS (such as Overcast's web player).