Bug #17029

URI.parse considers invalid when browsers consider it valid

Added by nileshtr (Nilesh Trivedi) 26 days ago. Updated 17 days ago.

Target version:
ruby -v:
ruby 2.7.1p83 (2020-03-31 revision a0c7c23c9c) [x86_64-darwin19]


I have a form with <input type="url" required> and in the backend, I try to extract the domain with URI.parse(url).host

A user was able to submit a value like which passed the browser's validation check, but failed by URI.parse with this error:

        3: from /Users/helix/.rbenv/versions/2.7.1/lib/ruby/2.7.0/uri/common.rb:234:in `parse'
        2: from /Users/helix/.rbenv/versions/2.7.1/lib/ruby/2.7.0/uri/rfc3986_parser.rb:73:in `parse'
        1: from /Users/helix/.rbenv/versions/2.7.1/lib/ruby/2.7.0/uri/rfc3986_parser.rb:67:in `split'
URI::InvalidURIError (bad URI(is not URI?): "")

You can try the browser's behavior at MDN's demo:

This is what the MDN page says about validation:

The syntax of a URL is fairly intricate. It's defined by WHATWG's URL Living Standard ( ) and is described for newcomers in our article What is a URL? ( )

Updated by jeremyevans0 (Jeremy Evans) 26 days ago

This does seem like a bug to me. It looks like should be an valid URL with a fragment of ##. However, the uri library is maintained in a separate repository. Please submit this as an issue to

Updated by phluid61 (Matthew Kerwin) 26 days ago

It's not valid according to RFC 3986 (the URI standard) but that is pretty old now. I suspect switching from the IETF URI spec to the WHATWG URL spec would have other consequences, too.

Updated by nileshtr (Nilesh Trivedi) 21 days ago

I filed an issue at the uri library's Github repo:


Updated by jeremyevans0 (Jeremy Evans) 17 days ago

  • Status changed from Open to Closed

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