Sync.com Compatibility Mode

What is Compatibility Mode?

When you download your files directly from the web panel Sync uses advanced HTML5 local web browser storage technology to decrypt the files locally, while they’re downloading.

This zero-knowledge feature is fully supported by Chrome (files up to 25GB), Firefox (files up to 500MB in size), Internet Explorer 10+ (files up to 500MB in size) and Microsoft Edge (files up to 500MB in size). This feature is not fully supported by Safari, and some mobile browsers.

If you attempt to download a file that can’t be decrypted by the web browser locally, Sync will give you the option to download the file in “compatibility mode”. With compatibility mode, the download will stream through a Sync mem-cache to help your web browser with local decryption. Of course, the link is still fully encrypted in transit, and the decrypted link data and encryption keys are never stored by Sync. The benefit of compatibility mode is that that there are no file size limits, and virtually all web browsers (eg. Safari) are fully supported. The compatibility mode download option is also available if you right click on any of your files in the web panel.

It’s important to note that Sync will NEVER default to compatibility mode, and always provide warning.
The choice is always yours.

What’s up with Safari?

Apple has not yet implemented the full HTML5 local storage spec. Specifically there is a long standing bug (link: https://bugs.webkit.org/show_bug.cgi?id=102914) with Webkit Gtk that has been discussed, but not resolved, for the past 2 years! We’re hoping Apple will get this fixed soon.