diff --git a/Tests/LibWeb/Text/expected/DOM/Document-createElementNS-uppercase.txt b/Tests/LibWeb/Text/expected/DOM/Document-createElementNS-uppercase.txt
new file mode 100644
index 0000000000000..cc49db201bb39
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/DOM/Document-createElementNS-uppercase.txt
@@ -0,0 +1,2 @@
+element named "DIV" is instance of HTMLUnknownElement: true
+element named "div" is instance of HTMLDivElement: true
diff --git a/Tests/LibWeb/Text/input/DOM/Document-createElementNS-uppercase.html b/Tests/LibWeb/Text/input/DOM/Document-createElementNS-uppercase.html
new file mode 100644
index 0000000000000..8677bd7b7a2b3
--- /dev/null
+++ b/Tests/LibWeb/Text/input/DOM/Document-createElementNS-uppercase.html
@@ -0,0 +1,11 @@
+
+
+
diff --git a/Userland/Libraries/LibWeb/DOM/ElementFactory.cpp b/Userland/Libraries/LibWeb/DOM/ElementFactory.cpp
index e10cc9c4ca216..aed7fd79a662c 100644
--- a/Userland/Libraries/LibWeb/DOM/ElementFactory.cpp
+++ b/Userland/Libraries/LibWeb/DOM/ElementFactory.cpp
@@ -276,148 +276,148 @@ bool is_unknown_html_element(FlyString const& tag_name)
// https://html.spec.whatwg.org/#elements-in-the-dom:element-interface
static JS::NonnullGCPtr create_html_element(JS::Realm& realm, Document& document, QualifiedName qualified_name)
{
- FlyString lowercase_tag_name = MUST(Infra::to_ascii_lowercase(qualified_name.local_name()));
+ FlyString tag_name = qualified_name.local_name();
- if (lowercase_tag_name == HTML::TagNames::a)
+ if (tag_name == HTML::TagNames::a)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::area)
+ if (tag_name == HTML::TagNames::area)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::audio)
+ if (tag_name == HTML::TagNames::audio)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::base)
+ if (tag_name == HTML::TagNames::base)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::body)
+ if (tag_name == HTML::TagNames::body)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::br)
+ if (tag_name == HTML::TagNames::br)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::button)
+ if (tag_name == HTML::TagNames::button)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::canvas)
+ if (tag_name == HTML::TagNames::canvas)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::data)
+ if (tag_name == HTML::TagNames::data)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::datalist)
+ if (tag_name == HTML::TagNames::datalist)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::details)
+ if (tag_name == HTML::TagNames::details)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::dialog)
+ if (tag_name == HTML::TagNames::dialog)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::dir)
+ if (tag_name == HTML::TagNames::dir)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::div)
+ if (tag_name == HTML::TagNames::div)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::dl)
+ if (tag_name == HTML::TagNames::dl)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::embed)
+ if (tag_name == HTML::TagNames::embed)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::fieldset)
+ if (tag_name == HTML::TagNames::fieldset)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::font)
+ if (tag_name == HTML::TagNames::font)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::form)
+ if (tag_name == HTML::TagNames::form)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::frame)
+ if (tag_name == HTML::TagNames::frame)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::frameset)
+ if (tag_name == HTML::TagNames::frameset)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::head)
+ if (tag_name == HTML::TagNames::head)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name.is_one_of(HTML::TagNames::h1, HTML::TagNames::h2, HTML::TagNames::h3, HTML::TagNames::h4, HTML::TagNames::h5, HTML::TagNames::h6))
+ if (tag_name.is_one_of(HTML::TagNames::h1, HTML::TagNames::h2, HTML::TagNames::h3, HTML::TagNames::h4, HTML::TagNames::h5, HTML::TagNames::h6))
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::hr)
+ if (tag_name == HTML::TagNames::hr)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::html)
+ if (tag_name == HTML::TagNames::html)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::iframe)
+ if (tag_name == HTML::TagNames::iframe)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::img)
+ if (tag_name == HTML::TagNames::img)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::input)
+ if (tag_name == HTML::TagNames::input)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::label)
+ if (tag_name == HTML::TagNames::label)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::legend)
+ if (tag_name == HTML::TagNames::legend)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::li)
+ if (tag_name == HTML::TagNames::li)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::link)
+ if (tag_name == HTML::TagNames::link)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::map)
+ if (tag_name == HTML::TagNames::map)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::marquee)
+ if (tag_name == HTML::TagNames::marquee)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::menu)
+ if (tag_name == HTML::TagNames::menu)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::meta)
+ if (tag_name == HTML::TagNames::meta)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::meter)
+ if (tag_name == HTML::TagNames::meter)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name.is_one_of(HTML::TagNames::ins, HTML::TagNames::del))
+ if (tag_name.is_one_of(HTML::TagNames::ins, HTML::TagNames::del))
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::object)
+ if (tag_name == HTML::TagNames::object)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::ol)
+ if (tag_name == HTML::TagNames::ol)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::optgroup)
+ if (tag_name == HTML::TagNames::optgroup)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::option)
+ if (tag_name == HTML::TagNames::option)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::output)
+ if (tag_name == HTML::TagNames::output)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::p)
+ if (tag_name == HTML::TagNames::p)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::param)
+ if (tag_name == HTML::TagNames::param)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::picture)
+ if (tag_name == HTML::TagNames::picture)
return realm.heap().allocate(realm, document, move(qualified_name));
// NOTE: The obsolete elements "listing" and "xmp" are explicitly mapped to HTMLPreElement in the specification.
- if (lowercase_tag_name.is_one_of(HTML::TagNames::pre, HTML::TagNames::listing, HTML::TagNames::xmp))
+ if (tag_name.is_one_of(HTML::TagNames::pre, HTML::TagNames::listing, HTML::TagNames::xmp))
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::progress)
+ if (tag_name == HTML::TagNames::progress)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name.is_one_of(HTML::TagNames::blockquote, HTML::TagNames::q))
+ if (tag_name.is_one_of(HTML::TagNames::blockquote, HTML::TagNames::q))
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::script)
+ if (tag_name == HTML::TagNames::script)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::select)
+ if (tag_name == HTML::TagNames::select)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::slot)
+ if (tag_name == HTML::TagNames::slot)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::source)
+ if (tag_name == HTML::TagNames::source)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::span)
+ if (tag_name == HTML::TagNames::span)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::style)
+ if (tag_name == HTML::TagNames::style)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::summary)
+ if (tag_name == HTML::TagNames::summary)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::caption)
+ if (tag_name == HTML::TagNames::caption)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name.is_one_of(Web::HTML::TagNames::td, Web::HTML::TagNames::th))
+ if (tag_name.is_one_of(Web::HTML::TagNames::td, Web::HTML::TagNames::th))
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name.is_one_of(HTML::TagNames::colgroup, HTML::TagNames::col))
+ if (tag_name.is_one_of(HTML::TagNames::colgroup, HTML::TagNames::col))
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::table)
+ if (tag_name == HTML::TagNames::table)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::tr)
+ if (tag_name == HTML::TagNames::tr)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name.is_one_of(HTML::TagNames::tbody, HTML::TagNames::thead, HTML::TagNames::tfoot))
+ if (tag_name.is_one_of(HTML::TagNames::tbody, HTML::TagNames::thead, HTML::TagNames::tfoot))
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::template_)
+ if (tag_name == HTML::TagNames::template_)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::textarea)
+ if (tag_name == HTML::TagNames::textarea)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::time)
+ if (tag_name == HTML::TagNames::time)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::title)
+ if (tag_name == HTML::TagNames::title)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::track)
+ if (tag_name == HTML::TagNames::track)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::ul)
+ if (tag_name == HTML::TagNames::ul)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name == HTML::TagNames::video)
+ if (tag_name == HTML::TagNames::video)
return realm.heap().allocate(realm, document, move(qualified_name));
- if (lowercase_tag_name.is_one_of(
+ if (tag_name.is_one_of(
HTML::TagNames::article, HTML::TagNames::section, HTML::TagNames::nav, HTML::TagNames::aside, HTML::TagNames::hgroup, HTML::TagNames::header, HTML::TagNames::footer, HTML::TagNames::address, HTML::TagNames::dt, HTML::TagNames::dd, HTML::TagNames::figure, HTML::TagNames::figcaption, HTML::TagNames::main, HTML::TagNames::em, HTML::TagNames::strong, HTML::TagNames::small, HTML::TagNames::s, HTML::TagNames::cite, HTML::TagNames::dfn, HTML::TagNames::abbr, HTML::TagNames::ruby, HTML::TagNames::rt, HTML::TagNames::rp, HTML::TagNames::code, HTML::TagNames::var, HTML::TagNames::samp, HTML::TagNames::kbd, HTML::TagNames::sub, HTML::TagNames::sup, HTML::TagNames::i, HTML::TagNames::b, HTML::TagNames::u, HTML::TagNames::mark, HTML::TagNames::bdi, HTML::TagNames::bdo, HTML::TagNames::wbr, HTML::TagNames::noscript,
// Obsolete
HTML::TagNames::acronym, HTML::TagNames::basefont, HTML::TagNames::big, HTML::TagNames::center, HTML::TagNames::nobr, HTML::TagNames::noembed, HTML::TagNames::noframes, HTML::TagNames::plaintext, HTML::TagNames::rb, HTML::TagNames::rtc, HTML::TagNames::strike, HTML::TagNames::tt))