RSS Validators:

  • http://aggregator.userland.com/validator (RSS 0.91, RSS 0.92)
  • http://www.bath.ac.uk/~ccslrd/rss_validator/1.0/ (RSS 1.0)
  • http://www.bath.ac.uk/~ccslrd/rss_validator/ (RSS 0.9)
  • 0.9x infoSchematron Validator for RSS An RSS schema written in Schematron. It supports 0.9x and 1.0.
  • Redland RSS 1.0 Viewer (RSS 1.0) is RSS->HTML converter, but acts as validator also.