You can "buy" a digital copy in HD (720p or 1080p). Once purchased, you own the license and can download it to any compatible device.
If you already have a subscription, you can stream the film (and often download it for offline viewing within the app) on: Disney Plus : Frequently available on this platform globally. 500 Days Of Summer Download 720p
: Periodically hosts the film as part of its rotating romance library. You can "buy" a digital copy in HD (720p or 1080p)