I've heard Firefox keeps OPFS data in browser as long as there's enough space (which can be checked from JS). It's been reliable from my experience, but backup is still necessary by saving to remote server or export as local file. Safari has a stricter strategy and removes OPFS data and local storage more aggressively, for example, if a site domain hasn't been visited in 7 days.
On the File System Access API, it seems doubtful that Mozilla will ever implement it in a useful way.
> Mozilla's Position
> There's a subset of this API we're quite enthusiastic about (in particular providing a read/write API for files and directories as alternative storage endpoint), but it is wrapped together with aspects for which we do not think meaningful end user consent is possible to obtain (in particular cross-site access to the end user's local file system). Overall we consider this harmful therefore, but Mozilla could be supportive of parts, provided this were segmented better.
I've heard Firefox keeps OPFS data in browser as long as there's enough space (which can be checked from JS). It's been reliable from my experience, but backup is still necessary by saving to remote server or export as local file. Safari has a stricter strategy and removes OPFS data and local storage more aggressively, for example, if a site domain hasn't been visited in 7 days.
On the File System Access API, it seems doubtful that Mozilla will ever implement it in a useful way.
> Mozilla's Position
> There's a subset of this API we're quite enthusiastic about (in particular providing a read/write API for files and directories as alternative storage endpoint), but it is wrapped together with aspects for which we do not think meaningful end user consent is possible to obtain (in particular cross-site access to the end user's local file system). Overall we consider this harmful therefore, but Mozilla could be supportive of parts, provided this were segmented better.
https://mozilla.github.io/standards-positions/#native-file-s...