For those unfamiliar, differential sync lets users upload only the changes for large files. If you have a 1000-page word document but only re-write one page, it’s only that page that will be synced to the cloud. Previously, the feature only supported “modern Office file formats”. This cut out some of its most desirable use-cases, such as in .zip, AutoCAD, and TIFF files. For users on low-bandwidth connections or with data caps, it could prove a godsend. The expanded launch was first spotted by MSPowerUser via Microsoft’s official OneDrive roadmap. It’s not yet clear if the feature is enabled for all or if it will take a little while yet to reach every country. Either way, it marks the end of a years-long effort that experienced several roadblocks and delays. The feature has been on the roadmap since early 2017, and was marked as ‘thinking about it’ in 2014. However, it missed its published roadmap release window in 2017 and later admitted the inclusion on the document was a mistake. Things were very silent until May last year when Microsoft said it would make differential sync available for all file types later in 2019. Clearly, it didn’t hit that target either, but we’re at least at the finish line now. Though differential Office sync has been available for some time, this expansion is the functionality many have been anticipating. With so many working from home, it’s more important than ever that files on personal devices are backed up, and differential sync should make that possible on even low bandwidth connections.