Non-standard: This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The Metadata interface contains information about a file system entry. This metadata includes the file's size and modification date and time.
Note: This interface isn't available through the global scope; instead, you obtain a Metadata object describing a FileSystemEntry using the method FileSystemEntry.getMetadata().