Numeric character reference fallback for file upload characters not representable in form-charset

Change <input type="file"> filename encoding in multipart/form-data uploads in forms with non-Unicode accept-charset to use HTML numeric character references rather than '?' when a filename the user selects contains characters not representable in the target character encoding. This change would align our behavior with the existing behavior of Firefox and Edge. It is hoped that this behavior can eventually achieve cross-browser consensus and standardization.


From : "File names included in the generated multipart/form-data resource (as part of file fields) must use the character encoding selected above, though the precise name may be approximated if necessary (e.g. newlines could be removed from file names, quotes could be changed to "%22", and characters not expressible in the selected character encoding could be replaced by other characters)."


Status in Chromium


Proposed (tracking bug)

Consensus & Standardization

After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.

  • Shipped
  • Shipped
  • No public signals
  • No signals


Last updated on 2017-11-11