Cross-Origin Storage API: stop downloading twice

“Cross-Origin Storage” title with the subtitle “Share one copy of a file across origins” above a code editor window and the name Dennis Morello.

Dennis Morello explains a proposed browser standard that stores and retrieves large files by their SHA-256 hash instead of URLs, creating a shared cache across origins. A single requestFileHandle() method returns the file if present or downloads and stores it. Privacy is built in: no file enumeration, ambiguous not-found responses, and a public hash list for globally shared files.

morello.dev/blog/cross-origin-storage-api