The London Perl and Raku Workshop takes place on 26th Oct 2024. If your company depends on Perl, please consider sponsoring and/or attending.


URI::Escape::XS - Drop-In replacement for URI::Escape


$Id:,v 0.14 2016/06/09 11:09:14 dankogai Exp $


  # use it instead of URI::Escape
  use URI::Escape::XS qw/uri_escape uri_unescape/;
  $safe = uri_escape("10% is enough\n");
  $verysafe = uri_escape("foo", "\0-\377");
  $str  = uri_unescape($safe);

  # or use encodeURIComponent and decodeURIComponent
  use URI::Escape::XS;
  $safe = encodeURIComponent("10% is enough\n");
  $str  = decodeURIComponent("10%25%20is%20enough%0A");

  # if you have CNet::IDN::Encode installed
  $safe = encodeURIComponentIDN("http://ドメイン名例.jp/dan/");
  $str  = decodeURIComponentIDN("");


by default

"encodeURIComponent" and "decodeURIComponent"

"encodeURIComponentIDN" and "decodeURIComponentIDN" if either Net::LibIDN or Net::IDN::Encode is available

on demand

"uri_escape" and "uri_unescape"



Does what JavaScript's encodeURIComponent does.

  $uri = encodeURIComponent("");

Note you cannot customize characters to escape. If you need to do so, use "uri_escape".


Does what JavaScript's decodeURIComponent does.

  $str = decodeURIComponent("");

It decode not only %HH sequences but also %uHHHH sequences, with surrogate pairs correctly decoded.

  $str = decodeURIComponent("%uD869%uDEB2%u5F3E%u0061");
  # \x{2A6B2}\x{5F3E}a

This function UNCONDITIONALLY returns the decoded string with utf8 flag off. To get utf8-decoded string, use Encode and


This is the correct behavior because you cannot tell if the decoded string actually contains UTF-8 decoded string, like ISO-8859-1 and Shift_JIS.


Same as "encodeURIComponent" except that the host part is encoded in punycode. Either Net::LibIDN or Net::IDN::Encode is required to use this function.

URIs with Internationalizing Domain Names require two encodings: Punycode for host part and URI escape for the rest.

Currently only FULL URIs with http: or https: are supported.


Same as "decodeURIComponent" except that the host part is encoded in punycode. Either Net::LibIDN or Net::IDN::Encode is required to use this function.


Does exactly the same as URI::Escape::uri_escape() except when utf8-flagged string is fed.

URI::Escape::uri_escape() croak and urge you to uri_escape_utf8() but it is pointless because URI itself has no such things as utf8 flag. The function in this module ALWAYS TREATS the string as byte sequence. That way you can safely use this function without worrying about utf8 flags.

Note this function is NOT EXPORTED by default. That way you can use URI::Escape and URI::Escape::XS simultaneously.


Does exactly the same as URI::Escape::uri_escape() except when %uHHHH is fed.

URI::Escape::uri_unescape() simply ignores %uHHHH sequences while the function in this module does decode it into the corresponding UTF-8 byte sequence.

Like uri_escape, this function is NOT EXPORTED by default.

Note on the %uHHHH sequence

With this module the resulting strings never have the utf8 flag on. So if you want to decode it to perl utf8, You have to explicitly decode via Encode. Remember. URIs have always been a byte sequence, not UTF-8 characters.

If the %uHHHH sequence became standard, you could have safely told if a given URI is in Unicode. But more fortunately than unfortunately, the RFC proposal was rejected so you cannot tell which encoding is used just by looking at the URI.

I said fortunately because %uHHHH can be nasty for non-BMP characters. Since each %uHHHH can hold one 16-bit value, you need a surrogate pair to represent it if it is U+10000 and above.

In spite of that, there are a significant number of URIs with %uHHHH escapes. Therefore this module supports decoding only.


Since this module uses XS, it is really fast except for uri_escape("noop").

Regexp which is used in URI::Escape is really fast for non-matching but slows down significantly when it has to replace string.


On Macbook Pro 2GHz, Perl 5.8.8.
 Unescape it
 U::E      58526/s       --     -88%
 U::E::XS 486968/s     732%       --
 Escape it back
 U::E      30046/s       --     -78%
 U::E::XS 136992/s     356%       --
 Unescape it
               Rate     U::E U::E::XS
  U::E     821972/s       --      -4%
  U::E::XS 854732/s       4%       --
 Escape it back
 U::E::XS 522969/s       --      -7%
 U::E     565112/s       8%       --


Dan Kogai, <dankogai+cpan at>


Please report any bugs or feature requests to bug-uri-escape-xs at, or through the web interface at I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.


You can find documentation for this module with the perldoc command.

    perldoc URI::Escape::XS

You can also look for information at:


Gisle Aas for URI::Escape

Koichi Taniguchi for URI::Escape::JavaScript

Thomas Jacob for Net::LibIDN

Claus Färber for Net::IDN::Encode


Copyright 2007-2014 Dan Kogai, all rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.