diff --git a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp
index 0b8cc2bfdb..f2cc4cf384 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp
@@ -38,11 +38,11 @@ PropertyOwningCSSStyleDeclaration::PropertyOwningCSSStyleDeclaration(JS::Realm&
 {
 }
 
-DeprecatedString PropertyOwningCSSStyleDeclaration::item(size_t index) const
+String PropertyOwningCSSStyleDeclaration::item(size_t index) const
 {
     if (index >= m_properties.size())
         return {};
-    return CSS::string_from_property_id(m_properties[index].property_id);
+    return MUST(String::from_utf8(CSS::string_from_property_id(m_properties[index].property_id)));
 }
 
 JS::NonnullGCPtr<ElementInlineCSSStyleDeclaration> ElementInlineCSSStyleDeclaration::create(DOM::Element& element, Vector<StyleProperty> properties, HashMap<DeprecatedString, StyleProperty> custom_properties)
@@ -128,7 +128,7 @@ WebIDL::ExceptionOr<void> PropertyOwningCSSStyleDeclaration::set_property(Proper
 }
 
 // https://drafts.csswg.org/cssom/#dom-cssstyledeclaration-removeproperty
-WebIDL::ExceptionOr<DeprecatedString> PropertyOwningCSSStyleDeclaration::remove_property(PropertyID property_id)
+WebIDL::ExceptionOr<String> PropertyOwningCSSStyleDeclaration::remove_property(PropertyID property_id)
 {
     // 1. If the computed flag is set, then throw a NoModificationAllowedError exception.
     // NOTE: This is handled by the virtual override in ResolvedCSSStyleDeclaration.
@@ -202,7 +202,7 @@ bool PropertyOwningCSSStyleDeclaration::set_a_css_declaration(PropertyID propert
     return true;
 }
 
-DeprecatedString CSSStyleDeclaration::get_property_value(StringView property_name) const
+String CSSStyleDeclaration::get_property_value(StringView property_name) const
 {
     auto property_id = property_id_from_string(property_name);
     if (!property_id.has_value())
@@ -210,11 +210,11 @@ DeprecatedString CSSStyleDeclaration::get_property_value(StringView property_nam
     auto maybe_property = property(property_id.value());
     if (!maybe_property.has_value())
         return {};
-    return maybe_property->value->to_string().to_deprecated_string();
+    return maybe_property->value->to_string();
 }
 
 // https://drafts.csswg.org/cssom/#dom-cssstyledeclaration-getpropertypriority
-DeprecatedString CSSStyleDeclaration::get_property_priority(StringView property_name) const
+StringView CSSStyleDeclaration::get_property_priority(StringView property_name) const
 {
     auto property_id = property_id_from_string(property_name);
     if (!property_id.has_value())
@@ -222,7 +222,7 @@ DeprecatedString CSSStyleDeclaration::get_property_priority(StringView property_
     auto maybe_property = property(property_id.value());
     if (!maybe_property.has_value())
         return {};
-    return maybe_property->important == Important::Yes ? "important" : "";
+    return maybe_property->important == Important::Yes ? "important"sv : ""sv;
 }
 
 WebIDL::ExceptionOr<void> CSSStyleDeclaration::set_property(StringView property_name, StringView css_text, StringView priority)
@@ -233,11 +233,11 @@ WebIDL::ExceptionOr<void> CSSStyleDeclaration::set_property(StringView property_
     return set_property(property_id.value(), css_text, priority);
 }
 
-WebIDL::ExceptionOr<DeprecatedString> CSSStyleDeclaration::remove_property(StringView property_name)
+WebIDL::ExceptionOr<String> CSSStyleDeclaration::remove_property(StringView property_name)
 {
     auto property_id = property_id_from_string(property_name);
     if (!property_id.has_value())
-        return DeprecatedString::empty();
+        return String {};
     return remove_property(property_id.value());
 }
 
diff --git a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.h b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.h
index 1766738932..b3b0802cbc 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.h
@@ -22,18 +22,18 @@ public:
     virtual void initialize(JS::Realm&) override;
 
     virtual size_t length() const = 0;
-    virtual DeprecatedString item(size_t index) const = 0;
+    virtual String item(size_t index) const = 0;
 
     virtual Optional<StyleProperty> property(PropertyID) const = 0;
 
     virtual WebIDL::ExceptionOr<void> set_property(PropertyID, StringView css_text, StringView priority = ""sv) = 0;
-    virtual WebIDL::ExceptionOr<DeprecatedString> remove_property(PropertyID) = 0;
+    virtual WebIDL::ExceptionOr<String> remove_property(PropertyID) = 0;
 
     WebIDL::ExceptionOr<void> set_property(StringView property_name, StringView css_text, StringView priority);
-    WebIDL::ExceptionOr<DeprecatedString> remove_property(StringView property_name);
+    WebIDL::ExceptionOr<String> remove_property(StringView property_name);
 
-    DeprecatedString get_property_value(StringView property) const;
-    DeprecatedString get_property_priority(StringView property) const;
+    String get_property_value(StringView property) const;
+    StringView get_property_priority(StringView property) const;
 
     DeprecatedString css_text() const;
     virtual WebIDL::ExceptionOr<void> set_css_text(StringView) = 0;
@@ -59,12 +59,12 @@ public:
     virtual ~PropertyOwningCSSStyleDeclaration() override = default;
 
     virtual size_t length() const override;
-    virtual DeprecatedString item(size_t index) const override;
+    virtual String item(size_t index) const override;
 
     virtual Optional<StyleProperty> property(PropertyID) const override;
 
     virtual WebIDL::ExceptionOr<void> set_property(PropertyID, StringView css_text, StringView priority) override;
-    virtual WebIDL::ExceptionOr<DeprecatedString> remove_property(PropertyID) override;
+    virtual WebIDL::ExceptionOr<String> remove_property(PropertyID) override;
 
     Vector<StyleProperty> const& properties() const { return m_properties; }
     HashMap<DeprecatedString, StyleProperty> const& custom_properties() const { return m_custom_properties; }
diff --git a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.idl b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.idl
index 51a5267b06..725ca646bc 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.idl
+++ b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.idl
@@ -1,5 +1,5 @@
 // https://drafts.csswg.org/cssom/#cssstyledeclaration
-[Exposed=Window, UseDeprecatedAKString]
+[Exposed=Window]
 interface CSSStyleDeclaration {
 
     [CEReactions] attribute CSSOMString cssText;
diff --git a/Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.cpp b/Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.cpp
index 919d2d07a2..6734d0fd9a 100644
--- a/Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.cpp
+++ b/Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.cpp
@@ -72,7 +72,7 @@ size_t ResolvedCSSStyleDeclaration::length() const
     return 0;
 }
 
-DeprecatedString ResolvedCSSStyleDeclaration::item(size_t index) const
+String ResolvedCSSStyleDeclaration::item(size_t index) const
 {
     (void)index;
     return {};
@@ -944,7 +944,7 @@ WebIDL::ExceptionOr<void> ResolvedCSSStyleDeclaration::set_property(PropertyID,
 }
 
 // https://drafts.csswg.org/cssom/#dom-cssstyledeclaration-removeproperty
-WebIDL::ExceptionOr<DeprecatedString> ResolvedCSSStyleDeclaration::remove_property(PropertyID)
+WebIDL::ExceptionOr<String> ResolvedCSSStyleDeclaration::remove_property(PropertyID)
 {
     // 1. If the computed flag is set, then throw a NoModificationAllowedError exception.
     return WebIDL::NoModificationAllowedError::create(realm(), "Cannot remove properties from result of getComputedStyle()"_fly_string);
diff --git a/Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.h b/Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.h
index c46851ce32..6b3d8c5222 100644
--- a/Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.h
+++ b/Userland/Libraries/LibWeb/CSS/ResolvedCSSStyleDeclaration.h
@@ -19,10 +19,10 @@ public:
     virtual ~ResolvedCSSStyleDeclaration() override = default;
 
     virtual size_t length() const override;
-    virtual DeprecatedString item(size_t index) const override;
+    virtual String item(size_t index) const override;
     virtual Optional<StyleProperty> property(PropertyID) const override;
     virtual WebIDL::ExceptionOr<void> set_property(PropertyID, StringView css_text, StringView priority) override;
-    virtual WebIDL::ExceptionOr<DeprecatedString> remove_property(PropertyID) override;
+    virtual WebIDL::ExceptionOr<String> remove_property(PropertyID) override;
 
     virtual DeprecatedString serialized() const override;
     virtual WebIDL::ExceptionOr<void> set_css_text(StringView) override;