diff --git a/Tests/LibUnicode/TestUnicodeLocale.cpp b/Tests/LibUnicode/TestUnicodeLocale.cpp
index 5a14288f1a2..52dca559152 100644
--- a/Tests/LibUnicode/TestUnicodeLocale.cpp
+++ b/Tests/LibUnicode/TestUnicodeLocale.cpp
@@ -75,7 +75,7 @@ TEST_CASE(parse_unicode_locale_id)
         auto locale_id = Unicode::parse_unicode_locale_id(locale);
         EXPECT(!locale_id.has_value());
     };
-    auto pass = [](StringView locale, Optional<StringView> expected_language, Optional<StringView> expected_script, Optional<StringView> expected_region, Vector<StringView> expected_variants) {
+    auto pass = [](StringView locale, Optional<StringView> expected_language, Optional<StringView> expected_script, Optional<StringView> expected_region, Vector<String> expected_variants) {
         auto locale_id = Unicode::parse_unicode_locale_id(locale);
         VERIFY(locale_id.has_value());
 
@@ -252,7 +252,7 @@ TEST_CASE(parse_unicode_locale_id_with_private_use_extension)
         auto locale_id = Unicode::parse_unicode_locale_id(locale);
         EXPECT(!locale_id.has_value());
     };
-    auto pass = [](StringView locale, Vector<StringView> const& expected_extension) {
+    auto pass = [](StringView locale, Vector<String> const& expected_extension) {
         auto locale_id = Unicode::parse_unicode_locale_id(locale);
         VERIFY(locale_id.has_value());
         EXPECT_EQ(locale_id->private_use_extensions, expected_extension);
diff --git a/Userland/Libraries/LibJS/Runtime/Intl/AbstractOperations.cpp b/Userland/Libraries/LibJS/Runtime/Intl/AbstractOperations.cpp
index 767a92847c1..29609ac4153 100644
--- a/Userland/Libraries/LibJS/Runtime/Intl/AbstractOperations.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Intl/AbstractOperations.cpp
@@ -19,7 +19,7 @@ namespace JS::Intl {
 // 6.2.2 IsStructurallyValidLanguageTag ( locale ), https://tc39.es/ecma402/#sec-isstructurallyvalidlanguagetag
 static Optional<Unicode::LocaleID> is_structurally_valid_language_tag(StringView locale)
 {
-    auto contains_duplicate_variant = [](Vector<StringView>& variants) {
+    auto contains_duplicate_variant = [](auto& variants) {
         if (variants.is_empty())
             return false;
 
diff --git a/Userland/Libraries/LibUnicode/Locale.cpp b/Userland/Libraries/LibUnicode/Locale.cpp
index 62691697474..e9f8c3a6e9e 100644
--- a/Userland/Libraries/LibUnicode/Locale.cpp
+++ b/Userland/Libraries/LibUnicode/Locale.cpp
@@ -400,7 +400,7 @@ static Optional<Extension> parse_extension(GenericLexer& lexer)
     return {};
 }
 
-static Vector<StringView> parse_private_use_extensions(GenericLexer& lexer)
+static Vector<String> parse_private_use_extensions(GenericLexer& lexer)
 {
     // https://unicode.org/reports/tr35/#pu_extensions
     //
@@ -411,8 +411,8 @@ static Vector<StringView> parse_private_use_extensions(GenericLexer& lexer)
     if (!header.has_value())
         return {};
 
-    auto parse_values = [&]() -> Vector<StringView> {
-        Vector<StringView> extensions;
+    auto parse_values = [&]() -> Vector<String> {
+        Vector<String> extensions;
 
         while (true) {
             auto segment = consume_next_segment(lexer);
@@ -491,18 +491,18 @@ Optional<String> canonicalize_unicode_locale_id(LocaleID& locale_id)
         Title,
     };
 
-    auto append_sep_and_string = [&](Optional<StringView> const& string, Case case_ = Case::Lower) {
+    auto append_sep_and_string = [&](Optional<String> const& string, Case case_ = Case::Lower) {
         if (!string.has_value())
             return;
         switch (case_) {
         case Case::Upper:
-            builder.appendff("-{}", string->to_uppercase_string());
+            builder.appendff("-{}", string->to_uppercase());
             break;
         case Case::Lower:
-            builder.appendff("-{}", string->to_lowercase_string());
+            builder.appendff("-{}", string->to_lowercase());
             break;
         case Case::Title:
-            builder.appendff("-{}", string->to_titlecase_string());
+            builder.appendff("-{}", string->to_titlecase());
             break;
         }
     };
@@ -510,7 +510,7 @@ Optional<String> canonicalize_unicode_locale_id(LocaleID& locale_id)
     if (!locale_id.language_id.language.has_value())
         return {};
 
-    builder.append(locale_id.language_id.language->to_lowercase_string());
+    builder.append(locale_id.language_id.language->to_lowercase());
     append_sep_and_string(locale_id.language_id.script, Case::Title);
     append_sep_and_string(locale_id.language_id.region, Case::Upper);
 
diff --git a/Userland/Libraries/LibUnicode/Locale.h b/Userland/Libraries/LibUnicode/Locale.h
index 5fc244e5ed1..e570c0e15bc 100644
--- a/Userland/Libraries/LibUnicode/Locale.h
+++ b/Userland/Libraries/LibUnicode/Locale.h
@@ -17,25 +17,25 @@ namespace Unicode {
 
 struct LanguageID {
     bool is_root { false };
-    Optional<StringView> language {};
-    Optional<StringView> script {};
-    Optional<StringView> region {};
-    Vector<StringView> variants {};
+    Optional<String> language {};
+    Optional<String> script {};
+    Optional<String> region {};
+    Vector<String> variants {};
 };
 
 struct Keyword {
-    StringView key {};
-    Vector<StringView> types {};
+    String key {};
+    Vector<String> types {};
 };
 
 struct LocaleExtension {
-    Vector<StringView> attributes {};
+    Vector<String> attributes {};
     Vector<Keyword> keywords {};
 };
 
 struct TransformedField {
-    StringView key;
-    Vector<StringView> values {};
+    String key;
+    Vector<String> values {};
 };
 
 struct TransformedExtension {
@@ -45,7 +45,7 @@ struct TransformedExtension {
 
 struct OtherExtension {
     char key {};
-    Vector<StringView> values {};
+    Vector<String> values {};
 };
 
 using Extension = Variant<LocaleExtension, TransformedExtension, OtherExtension>;
@@ -53,7 +53,7 @@ using Extension = Variant<LocaleExtension, TransformedExtension, OtherExtension>
 struct LocaleID {
     LanguageID language_id {};
     Vector<Extension> extensions {};
-    Vector<StringView> private_use_extensions {};
+    Vector<String> private_use_extensions {};
 };
 
 // Note: These methods only verify that the provided strings match the EBNF grammar of the