diff --git a/Userland/Libraries/LibWeb/DOM/DOMTokenList.cpp b/Userland/Libraries/LibWeb/DOM/DOMTokenList.cpp
index 653215b746..fa75e738fb 100644
--- a/Userland/Libraries/LibWeb/DOM/DOMTokenList.cpp
+++ b/Userland/Libraries/LibWeb/DOM/DOMTokenList.cpp
@@ -5,11 +5,11 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
-#include <AK/CharacterTypes.h>
 #include <AK/StringBuilder.h>
 #include <LibWeb/DOM/DOMTokenList.h>
 #include <LibWeb/DOM/Document.h>
 #include <LibWeb/DOM/Element.h>
+#include <LibWeb/Infra/CharacterTypes.h>
 #include <LibWeb/WebIDL/DOMException.h>
 
 namespace {
@@ -234,7 +234,7 @@ WebIDL::ExceptionOr<void> DOMTokenList::validate_token(StringView token) const
 {
     if (token.is_empty())
         return WebIDL::SyntaxError::create(realm(), "Non-empty DOM tokens are not allowed");
-    if (any_of(token, is_ascii_space))
+    if (any_of(token, Infra::is_ascii_whitespace))
         return WebIDL::InvalidCharacterError::create(realm(), "DOM tokens containing ASCII whitespace are not allowed");
     return {};
 }
diff --git a/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp b/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp
index 8e716b708e..fc2aa0df6b 100644
--- a/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp
+++ b/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp
@@ -17,6 +17,7 @@
 #include <LibWeb/HTML/ImageData.h>
 #include <LibWeb/HTML/Path2D.h>
 #include <LibWeb/HTML/TextMetrics.h>
+#include <LibWeb/Infra/CharacterTypes.h>
 #include <LibWeb/Layout/TextNode.h>
 #include <LibWeb/Platform/FontPlugin.h>
 #include <LibWeb/WebIDL/ExceptionOr.h>
@@ -393,11 +394,9 @@ CanvasRenderingContext2D::PreparedText CanvasRenderingContext2D::prepare_text(St
     }
 
     // 2. Replace all ASCII whitespace in text with U+0020 SPACE characters.
-    // NOTE: This also replaces vertical tabs with space even though WHATWG
-    //       doesn't consider it as whitespace.
     StringBuilder builder { text.length() };
     for (auto c : text) {
-        builder.append(is_ascii_space(c) ? ' ' : c);
+        builder.append(Infra::is_ascii_whitespace(c) ? ' ' : c);
     }
     String replaced_text = builder.build();
 
diff --git a/Userland/Libraries/LibWeb/HTML/Parser/HTMLEncodingDetection.cpp b/Userland/Libraries/LibWeb/HTML/Parser/HTMLEncodingDetection.cpp
index 7ec96151e9..094359962a 100644
--- a/Userland/Libraries/LibWeb/HTML/Parser/HTMLEncodingDetection.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Parser/HTMLEncodingDetection.cpp
@@ -12,6 +12,7 @@
 #include <LibWeb/DOM/Attr.h>
 #include <LibWeb/DOM/Document.h>
 #include <LibWeb/HTML/Parser/HTMLEncodingDetection.h>
+#include <LibWeb/Infra/CharacterTypes.h>
 #include <ctype.h>
 
 namespace Web::HTML {
@@ -50,8 +51,7 @@ Optional<StringView> extract_character_encoding_from_meta_element(String const&
         lexer.ignore(charset_index.value() + 7);
 
         lexer.ignore_while([](char c) {
-            // FIXME: Not the exact same ASCII whitespace. The spec does not include vertical tab (\v).
-            return is_ascii_space(c);
+            return Infra::is_ascii_whitespace(c);
         });
 
         if (lexer.peek() != '=')
@@ -64,8 +64,7 @@ Optional<StringView> extract_character_encoding_from_meta_element(String const&
     lexer.ignore();
 
     lexer.ignore_while([](char c) {
-        // FIXME: Not the exact same ASCII whitespace. The spec does not include vertical tab (\v).
-        return is_ascii_space(c);
+        return Infra::is_ascii_whitespace(c);
     });
 
     if (lexer.is_eof())
@@ -90,8 +89,7 @@ Optional<StringView> extract_character_encoding_from_meta_element(String const&
     }
 
     auto encoding = lexer.consume_until([](char c) {
-        // FIXME: Not the exact same ASCII whitespace. The spec does not include vertical tab (\v).
-        return is_ascii_space(c) || c == ';';
+        return Infra::is_ascii_whitespace(c) || c == ';';
     });
     return TextCodec::get_standardized_encoding(encoding);
 }
diff --git a/Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.cpp b/Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.cpp
index 325dfd1b96..34389a6ae6 100644
--- a/Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.cpp
@@ -28,6 +28,7 @@
 #include <LibWeb/HTML/Parser/HTMLParser.h>
 #include <LibWeb/HTML/Parser/HTMLToken.h>
 #include <LibWeb/HTML/Window.h>
+#include <LibWeb/Infra/CharacterTypes.h>
 #include <LibWeb/Namespace.h>
 #include <LibWeb/SVG/TagNames.h>
 
@@ -3668,7 +3669,7 @@ RefPtr<CSS::StyleValue> parse_dimension_value(StringView string)
     auto position = input.begin();
 
     // 3. Skip ASCII whitespace within input given position.
-    while (position != input.end() && is_ascii_space(*position))
+    while (position != input.end() && Infra::is_ascii_whitespace(*position))
         ++position;
 
     // 4. If position is past the end of input or the code point at position within input is not an ASCII digit,