diff --git a/apps/openmw/mwclass/weapon.cpp b/apps/openmw/mwclass/weapon.cpp
index 464a331581..9dbdbfecb0 100644
--- a/apps/openmw/mwclass/weapon.cpp
+++ b/apps/openmw/mwclass/weapon.cpp
@@ -163,7 +163,7 @@ namespace MWClass
             text += "\n#{sType} ";
 
             int skill = MWMechanics::getWeaponType(ref->mBase->mData.mType)->mSkill;
-            const std::string type = ESM::Skill::sSkillNameIds[skill];
+            const std::string& type = ESM::Skill::sSkillNameIds[skill];
             std::string_view oneOrTwoHanded;
             if (weaponType->mWeaponClass == ESM::WeaponType::Melee)
             {
diff --git a/apps/openmw/mwgui/hud.cpp b/apps/openmw/mwgui/hud.cpp
index 9c4c4a1b7e..1d6b981bcd 100644
--- a/apps/openmw/mwgui/hud.cpp
+++ b/apps/openmw/mwgui/hud.cpp
@@ -393,7 +393,7 @@ namespace MWGui
         const ESM::Spell* spell =
             MWBase::Environment::get().getWorld()->getStore().get<ESM::Spell>().find(spellId);
 
-        std::string spellName = spell->mName;
+        const std::string& spellName = spell->mName;
         if (spellName != mSpellName && mSpellVisible)
         {
             mWeaponSpellTimer = 5.0f;
@@ -463,7 +463,7 @@ namespace MWGui
 
     void HUD::unsetSelectedSpell()
     {
-        std::string spellName = "#{sNone}";
+        std::string_view spellName = "#{sNone}";
         if (spellName != mSpellName && mSpellVisible)
         {
             mWeaponSpellTimer = 5.0f;
diff --git a/apps/openmw/mwgui/inventorywindow.cpp b/apps/openmw/mwgui/inventorywindow.cpp
index e7e30b76cf..1dfaa0d047 100644
--- a/apps/openmw/mwgui/inventorywindow.cpp
+++ b/apps/openmw/mwgui/inventorywindow.cpp
@@ -791,7 +791,7 @@ namespace MWGui
 
         int incr = next ? 1 : -1;
         bool found = false;
-        std::string lastId;
+        std::string_view lastId;
         if (selected != -1)
             lastId = model.getItem(selected).mBase.getCellRef().getRefId();
         ItemModel::ModelIndex cycled = selected;
diff --git a/apps/openmw/mwgui/mainmenu.cpp b/apps/openmw/mwgui/mainmenu.cpp
index 8fff838add..d77a2d0bcd 100644
--- a/apps/openmw/mwgui/mainmenu.cpp
+++ b/apps/openmw/mwgui/mainmenu.cpp
@@ -93,7 +93,7 @@ namespace MWGui
     {
         MWBase::WindowManager *winMgr = MWBase::Environment::get().getWindowManager();
 
-        std::string name = *sender->getUserData<std::string>();
+        const std::string& name = *sender->getUserData<std::string>();
         winMgr->playSound("Menu Click");
         if (name == "return")
         {
diff --git a/apps/openmw/mwgui/postprocessorhud.cpp b/apps/openmw/mwgui/postprocessorhud.cpp
index fc77f1e841..b7a25405b2 100644
--- a/apps/openmw/mwgui/postprocessorhud.cpp
+++ b/apps/openmw/mwgui/postprocessorhud.cpp
@@ -287,16 +287,16 @@ namespace MWGui
         while (mConfigArea->getChildCount() > 0)
             MyGUI::Gui::getInstance().destroyWidget(mConfigArea->getChildAt(0));
 
-        mShaderInfo->setCaption("");
+        mShaderInfo->setCaption({});
 
         std::ostringstream ss;
 
-        const std::string NA = "#{Interface:NotAvailableShort}";
-        const std::string endl = "\n";
+        const std::string_view NA = "#{Interface:NotAvailableShort}";
+        const char endl = '\n';
 
-        std::string author = technique->getAuthor().empty() ? NA : std::string(technique->getAuthor());
-        std::string version = technique->getVersion().empty() ? NA : std::string(technique->getVersion());
-        std::string description = technique->getDescription().empty() ? NA : std::string(technique->getDescription());
+        std::string_view author = technique->getAuthor().empty() ? NA : technique->getAuthor();
+        std::string_view version = technique->getVersion().empty() ? NA : technique->getVersion();
+        std::string_view description = technique->getDescription().empty() ? NA : technique->getDescription();
 
         auto serializeBool = [](bool value) {
             return value ? "#{sYes}" : "#{sNo}";
diff --git a/apps/openmw/mwgui/recharge.cpp b/apps/openmw/mwgui/recharge.cpp
index 3b3a754468..4c6a80540d 100644
--- a/apps/openmw/mwgui/recharge.cpp
+++ b/apps/openmw/mwgui/recharge.cpp
@@ -68,7 +68,7 @@ void Recharge::updateView()
 {
     MWWorld::Ptr gem = *mGemIcon->getUserData<MWWorld::Ptr>();
 
-    std::string soul = gem.getCellRef().getSoul();
+    const std::string& soul = gem.getCellRef().getSoul();
     const ESM::Creature *creature = MWBase::Environment::get().getWorld()->getStore().get<ESM::Creature>().find(soul);
 
     mChargeLabel->setCaptionWithReplacing("#{sCharges} " + MyGUI::utility::toString(creature->mData.mSoul));
diff --git a/apps/openmw/mwgui/savegamedialog.cpp b/apps/openmw/mwgui/savegamedialog.cpp
index 71127c26e1..ffa02f7c55 100644
--- a/apps/openmw/mwgui/savegamedialog.cpp
+++ b/apps/openmw/mwgui/savegamedialog.cpp
@@ -30,6 +30,7 @@
 #include "../mwstate/character.hpp"
 
 #include "confirmationdialog.hpp"
+#include "ustring.hpp"
 
 namespace MWGui
 {
@@ -177,7 +178,7 @@ namespace MWGui
 
                 // For a custom class, we will not find it in the store (unless we loaded the savegame first).
                 // Fall back to name stored in savegame header in that case.
-                std::string className;
+                std::string_view className;
                 if (it->getSignature().mPlayerClassId.empty())
                     className = it->getSignature().mPlayerClassName;
                 else
@@ -191,7 +192,7 @@ namespace MWGui
                         className = "?"; // From an older savegame format that did not support custom classes properly.
                 }
 
-                title << " (#{sLevel} " << it->getSignature().mPlayerLevel << " " << MyGUI::TextIterator::toTagsString(className) << ")";
+                title << " (#{sLevel} " << it->getSignature().mPlayerLevel << " " << MyGUI::TextIterator::toTagsString(toUString(className)) << ")";
 
                 mCharacterSelection->addItem (MyGUI::LanguageManager::getInstance().replaceTags(title.str()));
 
diff --git a/apps/openmw/mwgui/settingswindow.cpp b/apps/openmw/mwgui/settingswindow.cpp
index a646324c13..f24fafb855 100644
--- a/apps/openmw/mwgui/settingswindow.cpp
+++ b/apps/openmw/mwgui/settingswindow.cpp
@@ -238,7 +238,7 @@ namespace MWGui
         , mCurrentPage(-1)
     {
         bool terrain = Settings::Manager::getBool("distant terrain", "Terrain");
-        const std::string widgetName = terrain ? "RenderingDistanceSlider" : "LargeRenderingDistanceSlider";
+        const std::string_view widgetName = terrain ? "RenderingDistanceSlider" : "LargeRenderingDistanceSlider";
         MyGUI::Widget* unusedSlider;
         getWidget(unusedSlider, widgetName);
         unusedSlider->setVisible(false);
diff --git a/apps/openmw/mwgui/spellbuyingwindow.cpp b/apps/openmw/mwgui/spellbuyingwindow.cpp
index 7bd56c878d..dae157f511 100644
--- a/apps/openmw/mwgui/spellbuyingwindow.cpp
+++ b/apps/openmw/mwgui/spellbuyingwindow.cpp
@@ -34,10 +34,7 @@ namespace MWGui
 
     bool SpellBuyingWindow::sortSpells (const ESM::Spell* left, const ESM::Spell* right)
     {
-        std::string leftName = Misc::StringUtils::lowerCase(left->mName);
-        std::string rightName = Misc::StringUtils::lowerCase(right->mName);
-
-        return leftName.compare(rightName) < 0;
+        return Misc::StringUtils::ciLess(left->mName, right->mName);
     }
 
     void SpellBuyingWindow::addSpell(const ESM::Spell& spell)
diff --git a/apps/openmw/mwgui/spellcreationdialog.cpp b/apps/openmw/mwgui/spellcreationdialog.cpp
index 02b6ab8db6..a54c5c87f3 100644
--- a/apps/openmw/mwgui/spellcreationdialog.cpp
+++ b/apps/openmw/mwgui/spellcreationdialog.cpp
@@ -555,7 +555,7 @@ namespace MWGui
 
         for (const short effectId : knownEffects)
         {
-            std::string name = MWBase::Environment::get().getWorld ()->getStore ().get<ESM::GameSetting>().find(
+            const std::string& name = MWBase::Environment::get().getWorld ()->getStore ().get<ESM::GameSetting>().find(
                                                ESM::MagicEffect::effectIdToString(effectId))->mValue.getString();
             MyGUI::Widget* w = mAvailableEffectsList->getItemWidget(name);
 
diff --git a/apps/openmw/mwgui/spellicons.cpp b/apps/openmw/mwgui/spellicons.cpp
index 2f1da5857c..60ea47683b 100644
--- a/apps/openmw/mwgui/spellicons.cpp
+++ b/apps/openmw/mwgui/spellicons.cpp
@@ -149,7 +149,7 @@ namespace MWGui
                     image->setImageTexture(Misc::ResourceHelpers::correctIconPath(effect->mIcon,
                         MWBase::Environment::get().getResourceSystem()->getVFS()));
 
-                    std::string name = ESM::MagicEffect::effectIdToString (effectId);
+                    const std::string& name = ESM::MagicEffect::effectIdToString(effectId);
 
                     ToolTipInfo tooltipInfo;
                     tooltipInfo.caption = "#{" + name + "}";
diff --git a/apps/openmw/mwgui/spellwindow.cpp b/apps/openmw/mwgui/spellwindow.cpp
index c39341aeb4..20db95fc19 100644
--- a/apps/openmw/mwgui/spellwindow.cpp
+++ b/apps/openmw/mwgui/spellwindow.cpp
@@ -147,7 +147,7 @@ namespace MWGui
             MWBase::Environment::get().getWorld()->getStore().get<ESM::Spell>().find(spellId);
 
         MWWorld::Ptr player = MWMechanics::getPlayer();
-        std::string raceId = player.get<ESM::NPC>()->mBase->mRace;
+        const std::string& raceId = player.get<ESM::NPC>()->mBase->mRace;
         const ESM::Race* race = MWBase::Environment::get().getWorld()->getStore().get<ESM::Race>().find(raceId);
         // can't delete racial spells, birthsign spells or powers
         bool isInherent = race->mPowers.exists(spell->mId) || spell->mData.mType == ESM::Spell::ST_Power;
diff --git a/apps/openmw/mwgui/tooltips.cpp b/apps/openmw/mwgui/tooltips.cpp
index 353a88004e..94c4288ddf 100644
--- a/apps/openmw/mwgui/tooltips.cpp
+++ b/apps/openmw/mwgui/tooltips.cpp
@@ -400,9 +400,9 @@ namespace MWGui
         else
             mDynamicToolTipBox->changeWidgetSkin(MWBase::Environment::get().getWindowManager()->isGuiMode() ? "HUD_Box_NoTransp" : "HUD_Box");
 
-        std::string caption = info.caption;
-        std::string image = info.icon;
-        int imageSize = (image != "") ? info.imageSize : 0;
+        const std::string& caption = info.caption;
+        const std::string& image = info.icon;
+        int imageSize = (!image.empty()) ? info.imageSize : 0;
         std::string text = info.text;
 
         // remove the first newline (easier this way)
@@ -411,7 +411,7 @@ namespace MWGui
 
         const ESM::Enchantment* enchant = nullptr;
         const MWWorld::ESMStore& store = MWBase::Environment::get().getWorld()->getStore();
-        if (info.enchant != "")
+        if (!info.enchant.empty())
         {
             enchant = store.get<ESM::Enchantment>().search(info.enchant);
             if (enchant)
@@ -432,8 +432,8 @@ namespace MWGui
 
         const MyGUI::IntPoint padding(8, 8);
 
-        const int imageCaptionHPadding = (caption != "" ? 8 : 0);
-        const int imageCaptionVPadding = (caption != "" ? 4 : 0);
+        const int imageCaptionHPadding = !caption.empty() ? 8 : 0;
+        const int imageCaptionVPadding = !caption.empty() ? 4 : 0;
 
         const int maximumWidth = MyGUI::RenderManager::getInstance().getViewSize().width - imageCaptionHPadding * 2;
 
@@ -446,7 +446,7 @@ namespace MWGui
         captionWidget->setCaptionWithReplacing(caption);
         MyGUI::IntSize captionSize = captionWidget->getTextSize();
 
-        int captionHeight = std::max(caption != "" ? captionSize.height : 0, imageSize);
+        int captionHeight = std::max(!caption.empty() ? captionSize.height : 0, imageSize);
 
         Gui::EditBox* textWidget = mDynamicToolTipBox->createWidget<Gui::EditBox>("SandText", MyGUI::IntCoord(0, captionHeight+imageCaptionVPadding, 300, 300-captionHeight-imageCaptionVPadding), MyGUI::Align::Stretch, "ToolTipText");
         textWidget->setEditStatic(true);
@@ -458,8 +458,8 @@ namespace MWGui
         MyGUI::IntSize textSize = textWidget->getTextSize();
 
         captionSize += MyGUI::IntSize(imageSize, 0); // adjust for image
-        MyGUI::IntSize totalSize = MyGUI::IntSize( std::min(std::max(textSize.width,captionSize.width + ((image != "") ? imageCaptionHPadding : 0)),maximumWidth),
-            ((text != "") ? textSize.height + imageCaptionVPadding : 0) + captionHeight );
+        MyGUI::IntSize totalSize = MyGUI::IntSize( std::min(std::max(textSize.width,captionSize.width + ((!image.empty()) ? imageCaptionHPadding : 0)),maximumWidth),
+            (!text.empty() ? textSize.height + imageCaptionVPadding : 0) + captionHeight );
 
         for (const std::string& note : info.notes)
         {
@@ -578,7 +578,7 @@ namespace MWGui
 
         textWidget->setPosition (textWidget->getPosition() + MyGUI::IntPoint(0, padding.top)); // only apply vertical padding, the horizontal works automatically due to Align::HCenter
 
-        if (image != "")
+        if (!image.empty())
         {
             MyGUI::ImageBox* imageWidget = mDynamicToolTipBox->createWidget<MyGUI::ImageBox>("ImageBox",
                 MyGUI::IntCoord((totalSize.width - captionSize.width - imageCaptionHPadding)/2, 0, imageSize, imageSize),
@@ -611,7 +611,7 @@ namespace MWGui
     std::string ToolTips::getWeightString(const float weight, const std::string& prefix)
     {
         if (weight == 0)
-            return "";
+            return {};
         else
             return "\n" + prefix + ": " + toString(weight);
     }
@@ -619,7 +619,7 @@ namespace MWGui
     std::string ToolTips::getPercentString(const float value, const std::string& prefix)
     {
         if (value == 0)
-            return "";
+            return {};
         else
             return "\n" + prefix + ": " + toString(value*100) +"%";
     }
@@ -627,15 +627,15 @@ namespace MWGui
     std::string ToolTips::getValueString(const int value, const std::string& prefix)
     {
         if (value == 0)
-            return "";
+            return {};
         else
             return "\n" + prefix + ": " + toString(value);
     }
 
     std::string ToolTips::getMiscString(const std::string& text, const std::string& prefix)
     {
-        if (text == "")
-            return "";
+        if (text.empty())
+            return {};
         else
             return "\n" + prefix + ": " + text;
     }
@@ -643,7 +643,7 @@ namespace MWGui
     std::string ToolTips::getCountString(const int value)
     {
         if (value == 1)
-            return "";
+            return {};
         else
             return " (" + MyGUI::utility::toString(value) + ")";
     }
@@ -652,11 +652,11 @@ namespace MWGui
     {
         const std::string& soul = cellref.getSoul();
         if (soul.empty())
-            return std::string();
+            return {};
         const MWWorld::ESMStore &store = MWBase::Environment::get().getWorld()->getStore();
         const ESM::Creature *creature = store.get<ESM::Creature>().search(soul);
         if (!creature)
-            return std::string();
+            return {};
         if (creature->mName.empty())
             return " (" + creature->mId + ")";
         return " (" + creature->mName + ")";
@@ -677,7 +677,7 @@ namespace MWGui
                 if (cellref.getFactionRank() >= 0)
                 {
                     int rank = cellref.getFactionRank();
-                    const std::string rankName = fact->mRanks[rank];
+                    const std::string& rankName = fact->mRanks[rank];
                     if (rankName.empty())
                         ret += getValueString(cellref.getFactionRank(), "Rank");
                     else
@@ -802,9 +802,9 @@ namespace MWGui
         if (attributeId == -1)
             return;
 
-        std::string icon = ESM::Attribute::sAttributeIcons[attributeId];
-        std::string name = ESM::Attribute::sGmstAttributeIds[attributeId];
-        std::string desc = ESM::Attribute::sGmstAttributeDescIds[attributeId];
+        const std::string& icon = ESM::Attribute::sAttributeIcons[attributeId];
+        const std::string& name = ESM::Attribute::sGmstAttributeIds[attributeId];
+        const std::string& desc = ESM::Attribute::sGmstAttributeDescIds[attributeId];
 
         widget->setUserString("ToolTipType", "Layout");
         widget->setUserString("ToolTipLayout", "AttributeToolTip");
@@ -850,12 +850,9 @@ namespace MWGui
         widget->setUserString("ToolTipType", "Layout");
         widget->setUserString("ToolTipLayout", "BirthSignToolTip");
         widget->setUserString("ImageTexture_BirthSignImage", Misc::ResourceHelpers::correctTexturePath(sign->mTexture, vfs));
-        std::string text;
+        std::string text = sign->mName + "\n#{fontcolourhtml=normal}" + sign->mDescription;
 
-        text += sign->mName;
-        text += "\n#{fontcolourhtml=normal}" + sign->mDescription;
-
-        std::vector<std::string> abilities, powers, spells;
+        std::vector<const ESM::Spell*> abilities, powers, spells;
 
         for (const std::string& spellId : sign->mPowers.mList)
         {
@@ -867,35 +864,27 @@ namespace MWGui
                 continue; // We only want spell, ability and powers.
 
             if (type == ESM::Spell::ST_Ability)
-                abilities.push_back(spellId);
+                abilities.push_back(spell);
             else if (type == ESM::Spell::ST_Power)
-                powers.push_back(spellId);
+                powers.push_back(spell);
             else if (type == ESM::Spell::ST_Spell)
-                spells.push_back(spellId);
+                spells.push_back(spell);
         }
 
-        struct {
-            const std::vector<std::string> &spells;
-            std::string label;
-        }
-        categories[3] = {
-            {abilities, "sBirthsignmenu1"},
-            {powers,    "sPowers"},
-            {spells,    "sBirthsignmenu2"}
-        };
-
-        for (int category = 0; category < 3; ++category)
+        using Category = std::pair<const std::vector<const ESM::Spell*>&, std::string_view>;
+        for (const auto&[category, label] : std::initializer_list<Category>{{abilities, "sBirthsignmenu1"}, {powers, "sPowers"}, {spells, "sBirthsignmenu2"}})
         {
             bool addHeader = true;
-            for (const std::string& spellId : categories[category].spells)
+            for (const ESM::Spell* spell : category)
             {
                 if (addHeader)
                 {
-                    text += std::string("\n\n#{fontcolourhtml=header}") + std::string("#{") + categories[category].label + "}";
+                    text += "\n\n#{fontcolourhtml=header}#{";
+                    text += label;
+                    text += '}';
                     addHeader = false;
                 }
 
-                const ESM::Spell *spell = store.get<ESM::Spell>().find(spellId);
                 text += "\n#{fontcolourhtml=normal}" + spell->mName;
             }
         }
diff --git a/apps/openmw/mwmechanics/aipackage.cpp b/apps/openmw/mwmechanics/aipackage.cpp
index 58e8c4d901..edaa481f10 100644
--- a/apps/openmw/mwmechanics/aipackage.cpp
+++ b/apps/openmw/mwmechanics/aipackage.cpp
@@ -300,7 +300,7 @@ void MWMechanics::AiPackage::openDoors(const MWWorld::Ptr& actor)
             return;
         }
 
-        const std::string keyId = door.getCellRef().getKey();
+        const std::string& keyId = door.getCellRef().getKey();
         if (keyId.empty())
             return;
 
diff --git a/apps/openmw/mwmechanics/disease.hpp b/apps/openmw/mwmechanics/disease.hpp
index 034561ad92..e182886059 100644
--- a/apps/openmw/mwmechanics/disease.hpp
+++ b/apps/openmw/mwmechanics/disease.hpp
@@ -60,8 +60,7 @@ namespace MWMechanics
                 actor.getClass().getCreatureStats(actor).getSpells().add(spell);
                 MWBase::Environment::get().getWorld()->applyLoopingParticles(actor);
 
-                std::string msg = "sMagicContractDisease";
-                msg = MWBase::Environment::get().getWorld()->getStore().get<ESM::GameSetting>().find(msg)->mValue.getString();
+                std::string msg = MWBase::Environment::get().getWorld()->getStore().get<ESM::GameSetting>().find("sMagicContractDisease")->mValue.getString();
                 msg = Misc::StringUtils::format(msg, spell->mName);
                 MWBase::Environment::get().getWindowManager()->messageBox(msg);
             }
diff --git a/apps/openmw/mwworld/actionsoulgem.cpp b/apps/openmw/mwworld/actionsoulgem.cpp
index b416581fa7..dae0a4503f 100644
--- a/apps/openmw/mwworld/actionsoulgem.cpp
+++ b/apps/openmw/mwworld/actionsoulgem.cpp
@@ -30,7 +30,7 @@ namespace MWWorld
         }
 
         const auto& target = getTarget();
-        const std::string targetSoul = target.getCellRef().getSoul();
+        const std::string& targetSoul = target.getCellRef().getSoul();
 
         if (targetSoul.empty())
         {
diff --git a/apps/openmw/mwworld/containerstore.cpp b/apps/openmw/mwworld/containerstore.cpp
index f1288ee548..5f6df78b50 100644
--- a/apps/openmw/mwworld/containerstore.cpp
+++ b/apps/openmw/mwworld/containerstore.cpp
@@ -137,7 +137,7 @@ void MWWorld::ContainerStore::storeStates (const CellRefList<T>& collection,
     }
 }
 
-const std::string MWWorld::ContainerStore::sGoldId = "gold_001";
+const std::string_view MWWorld::ContainerStore::sGoldId = "gold_001";
 
 MWWorld::ContainerStore::ContainerStore()
     : mListener(nullptr)
diff --git a/apps/openmw/mwworld/containerstore.hpp b/apps/openmw/mwworld/containerstore.hpp
index f7f569ec97..94207e1df2 100644
--- a/apps/openmw/mwworld/containerstore.hpp
+++ b/apps/openmw/mwworld/containerstore.hpp
@@ -90,7 +90,7 @@ namespace MWWorld
 
             static constexpr int Type_All = 0xffff;
 
-            static const std::string sGoldId;
+            static const std::string_view sGoldId;
 
         protected:
             ContainerStoreListener* mListener;