Instagram is currently storing recently uploaded photos at higher resolutions than before, at a size of 1080x1080 pixels, compared to its previous 640x640.
The change was spotted by The Verge, and can be seen while navigating the Web version of Instagram, or with Instagram photos embedded on remote Web pages.
Instagram, contacted by The Verge, has declined to comment, but if you upload one of your photos to the service, you'll have the same pleasant surprise to have them stored at 1080x1080, just as we did below.
Older photos are still being stored in a 640x640 format, and it's highly unlikely that Instagram has preserved those photos at higher qualities on its server.
We'll be waiting for an official announcement in the coming days, and let's hope Instagram has other surprises for us as well (like a new layout).