XMarks is Dead on May 1st, 2018 : firefox
The Raindrop.io seems to work, but when I go to sort by name, there are some sites that are not sorted by name. For instance on my bookmark bar Yahoo! shows up before reddit in Raindrop.io
Xmarks Discontinued on May 1st: Here are 7 Xmarks Alternatives to Try
Raindrop is a freemium bookmark manager that is available on all platforms, browsers, and OS. Raindrop is available in two flavors. The free version will allow you to save and sync bookmarks across devices and OS. The paid version, for $3 a month, will allow you to find and delete duplicate entries, have nested collections, use tags, and check for broken links.
3+ Best XMarks Alternatives For Bookmarks Synchronization Across Multiple Browsers
Raindrop.io is another bookmarks synchronization service which is very much like Start.me but apart from the traditional bookmarks, it can save and organize other types of data like articles, photos, screenshots etc.