diff --git a/src/qml/Base/HInterfaceBox.qml b/src/qml/Base/HInterfaceBox.qml
index fb9bf6ef..c59feab0 100644
--- a/src/qml/Base/HInterfaceBox.qml
+++ b/src/qml/Base/HInterfaceBox.qml
@@ -15,8 +15,8 @@ HScalingBox {
     default property alias body: interfaceBody.children
 
     function clickEnterButtonTarget() {
-        for (var i = 0; i < buttonModel.length; i++) {
-            var btn = interfaceButtonsRepeater.itemAt(i)
+        for (let i = 0; i < buttonModel.length; i++) {
+            let btn = interfaceButtonsRepeater.itemAt(i)
             if (btn.name === enterButtonTarget) { btn.clicked() }
         }
     }
diff --git a/src/qml/Base/HListModel.qml b/src/qml/Base/HListModel.qml
index 80c9c9b8..e50cd30c 100644
--- a/src/qml/Base/HListModel.qml
+++ b/src/qml/Base/HListModel.qml
@@ -25,20 +25,18 @@ SortFilterProxyModel {
     }
 
     function extend(newItems) {
-        for (var i = 0; i < newItems.length; i++) {
-            model.append(newItems[i])
-        }
+        for (let item of newItems) { model.append(item) }
     }
 
     function getIndices(whereRolesAre, maxResults=null, maxTries=null) {
         // maxResults, maxTries: null or int
-        var results = []
+        let results = []
 
-        for (var i = 0; i < model.count; i++) {
-            var item    = model.get(i)
-            var include = true
+        for (let i = 0; i < model.count; i++) {
+            let item    = model.get(i)
+            let include = true
 
-            for (var role in whereRolesAre) {
+            for (let role in whereRolesAre) {
                 if (item[role] != whereRolesAre[role]) {
                     include = false
                     break
@@ -60,33 +58,31 @@ SortFilterProxyModel {
     }
 
     function getWhere(rolesAre, maxResults=null, maxTries=null) {
-        var indices = getIndices(rolesAre, maxResults, maxTries)
-        var items = []
+        let items = []
 
-        for (var i = 0; i < indices.length; i++) {
-            items.push(model.get(indices[i]))
+        for (let indice of getIndices(rolesAre, maxResults, maxTries)) {
+            items.push(model.get(indice))
         }
         return items
     }
 
     function forEachWhere(rolesAre, func, maxResults=null, maxTries=null) {
-        var items = getWhere(rolesAre, maxResults, maxTries)
-        for (var i = 0; i < items.length; i++) {
-            func(items[i])
+        for (let item of getWhere(rolesAre, maxResults, maxTries)) {
+            func(item)
         }
     }
 
     function upsert(
         whereRolesAre, newItem, updateIfExist=true, maxTries=null
     ) {
-        var indices = getIndices(whereRolesAre, 1, maxTries)
+        let indices = getIndices(whereRolesAre, 1, maxTries)
 
         if (indices.length == 0) {
             model.append(newItem)
             return model.get(model.count)
         }
 
-		var existing = model.get(indices[0])
+		let existing = model.get(indices[0])
         if (! updateIfExist) { return existing }
 
 		// Really update only if existing and new item have a difference
@@ -107,31 +103,29 @@ SortFilterProxyModel {
     }
 
     function pop(index) {
-        var item = model.get(index)
+        let item = model.get(index)
         model.remove(index)
         return item
     }
 
     function popWhere(rolesAre, maxResults=null, maxTries=null) {
-        var indices = getIndices(rolesAre, maxResults, maxTries)
-        var items = []
+        let items = []
 
-        for (var i = 0; i < indices.length; i++) {
-            items.push(model.get(indices[i]))
-            model.remove(indices[i])
+        for (let indice of getIndices(rolesAre, maxResults, maxTries)) {
+            items.push(model.get(indice))
+            model.remove(indice)
         }
         return items
     }
 
 
     function toObject(itemList=sortFilteredModel) {
-        var objList = []
+        let objList = []
 
-        for (var i = 0; i < itemList.count; i++) {
-            var item = itemList.get(i)
-            var obj  = JSON.parse(JSON.stringify(item))
+        for (let item of itemList) {
+            let obj = JSON.parse(JSON.stringify(item))
 
-            for (var role in obj) {
+            for (let role in obj) {
                 if (obj[role]["objectName"] != undefined) {
                     obj[role] = toObject(item[role])
                 }
diff --git a/src/qml/Chat/SendBox.qml b/src/qml/Chat/SendBox.qml
index b1846ce6..e369b8de 100644
--- a/src/qml/Chat/SendBox.qml
+++ b/src/qml/Chat/SendBox.qml
@@ -68,7 +68,7 @@ HRectangle {
 
                     if (textArea.text === "") { return }
 
-                    var args = [chatPage.roomId, textArea.text]
+                    let args = [chatPage.roomId, textArea.text]
                     py.callClientCoro(chatPage.userId, "send_markdown", args)
                     area.clear()
                 })
diff --git a/src/qml/Chat/Timeline/EventDelegate.qml b/src/qml/Chat/Timeline/EventDelegate.qml
index 33184203..c21b665d 100644
--- a/src/qml/Chat/Timeline/EventDelegate.qml
+++ b/src/qml/Chat/Timeline/EventDelegate.qml
@@ -58,7 +58,7 @@ Column {
     readonly property int verticalPadding: theme.spacing / 2
 
     ListView.onAdd: {
-        var nextDelegate = eventList.contentItem.children[index]
+        let nextDelegate = eventList.contentItem.children[index]
         if (nextDelegate) { nextDelegate.reloadPreviousItem() }
     }
 
diff --git a/src/qml/EventHandlers/rooms.js b/src/qml/EventHandlers/rooms.js
index 3ccf8aa4..500b6624 100644
--- a/src/qml/EventHandlers/rooms.js
+++ b/src/qml/EventHandlers/rooms.js
@@ -6,13 +6,11 @@
 Qt.include("../utils.js")
 
 function typingTextFor(members, ourUserId) {
-    var profiles = []
-    var names    = []
+    let profiles = []
+    let names    = []
 
-    for (var i = 0; i < members.length; i++) {
-        if (members[i] != ourUserId) {
-            profiles.push(users.find(members[i]))
-        }
+    for (let member of members) {
+        if (member != ourUserId) { profiles.push(users.find(member)) }
     }
 
     profiles.sort((left, right) => {
@@ -21,15 +19,14 @@ function typingTextFor(members, ourUserId) {
       return 0
     })
 
-    for (var i = 0; i < profiles.length; i++) {
-        var profile = profiles[i]
+    for (let profile of profiles) {
         names.push(coloredNameHtml(profile.displayName, profile.userId))
     }
 
     if (names.length == 0) { return "" }
     if (names.length == 1) { return qsTr("%1 is typing...").arg(names[0]) }
 
-    var text = qsTr("%1 and %2 are typing...")
+    let text = qsTr("%1 and %2 are typing...")
 
     if (names.length == 2) { return text.arg(names[0]).arg(names[1]) }
 
@@ -44,16 +41,16 @@ function onRoomUpdated(
     roomCategories.upsert({userId, name: category}, {userId, name: category})
 
     function find(category) {
-        var found = rooms.getIndices({userId, roomId, category}, 1)
+        let found = rooms.getIndices({userId, roomId, category}, 1)
         return found.length > 0 ? found[0] : null
     }
 
-    var replace = null
+    let replace = null
     if (category == "Invites")    { replace = find("Rooms") || find("Left") }
     else if (category == "Rooms") { replace = find("Invites") || find("Left") }
     else if (category == "Left")  { replace = find("Invites") || find("Rooms")}
 
-    var item = {
+    let item = {
         typingText: typingTextFor(typingMembers, userId),
 
         userId, category, roomId, displayName, avatarUrl, topic, members,
@@ -77,7 +74,7 @@ function onTimelineEventReceived(
     eventType, roomId, eventId, senderId, date, content,
     contentType, isLocalEcho, showNameLine, translatable, targetUserId
 ) {
-    var item = {
+    let item = {
         eventType: py.getattr(eventType, "__name__"),
 
         roomId, eventId, senderId, date, content, contentType, isLocalEcho,
@@ -90,7 +87,7 @@ function onTimelineEventReceived(
     }
 
     // Replace first matching local echo
-    var found = timelines.getIndices(
+    let found = timelines.getIndices(
         {roomId, senderId, content, "isLocalEcho": true}, 1, 250
     )
 
diff --git a/src/qml/Models/Timelines.qml b/src/qml/Models/Timelines.qml
index 38645158..1de29d6e 100644
--- a/src/qml/Models/Timelines.qml
+++ b/src/qml/Models/Timelines.qml
@@ -7,12 +7,11 @@ import "../Base"
 
 HListModel {
     function lastEventOf(roomId) {
-        // Return an event item or undefined if none found
-
-        for (var i = 0; i < count; i++) {
-            var item = get(i) // TODO: standardize
+        for (let i = 0; i < count; i++) {
+            let item = get(i) // TODO: standardize
             if (item.roomId == roomId) { return item }
         }
+        return null
     }
 
     sorters: ExpressionSorter {
diff --git a/src/qml/Models/Users.qml b/src/qml/Models/Users.qml
index db7ed8e5..465742c9 100644
--- a/src/qml/Models/Users.qml
+++ b/src/qml/Models/Users.qml
@@ -11,7 +11,7 @@ HListModel {
         // the expression with invalid data to establish property bindings
         if (! userId) { return }
 
-        var found = getWhere({userId}, 1)
+        let found = getWhere({userId}, 1)
         if (found.length > 0) { return found[0] }
 
         py.callCoro("request_user_update_event", [userId])
diff --git a/src/qml/Pages/EditAccount/Profile.qml b/src/qml/Pages/EditAccount/Profile.qml
index 6a080485..3e8151b8 100644
--- a/src/qml/Pages/EditAccount/Profile.qml
+++ b/src/qml/Pages/EditAccount/Profile.qml
@@ -21,7 +21,7 @@ HGridLayout {
 
         if (avatar.changed) {
             saveButton.avatarChangeRunning = true
-            var path = Qt.resolvedUrl(avatar.imageUrl).replace(/^file:/, "")
+            let path = Qt.resolvedUrl(avatar.imageUrl).replace(/^file:/, "")
 
             py.callClientCoro(
                 userId, "set_avatar_from_file", [path], response => {
diff --git a/src/qml/Pages/SignIn.qml b/src/qml/Pages/SignIn.qml
index c9aabf21..77ecc9c2 100644
--- a/src/qml/Pages/SignIn.qml
+++ b/src/qml/Pages/SignIn.qml
@@ -27,7 +27,7 @@ Item {
 
             login: button => {
                 button.loading = true
-                var args = [idField.text, passwordField.text]
+                let args = [idField.text, passwordField.text]
 
                 py.callCoro("login_client", args, userId => {
                     pageStack.showPage("RememberAccount", {loginWith, userId})
diff --git a/src/qml/Python.qml b/src/qml/Python.qml
index e4fff68f..25e5f709 100644
--- a/src/qml/Python.qml
+++ b/src/qml/Python.qml
@@ -20,14 +20,14 @@ Python {
     }
 
     function callCoro(name, args=[], callback=null) {
-        var uuid = Math.random() + "." + name
+        let uuid = Math.random() + "." + name
 
         pendingCoroutines[uuid] = callback || function() {}
         call("APP.call_backend_coro", [name, uuid, args])
     }
 
     function callClientCoro(accountId, name, args=[], callback=null) {
-        var uuid = Math.random() + "." + name
+        let uuid = Math.random() + "." + name
 
         pendingCoroutines[uuid] = callback || function() {}
         call("APP.call_client_coro", [accountId, name, uuid, args])
diff --git a/src/qml/UI.qml b/src/qml/UI.qml
index 42d41881..1961da88 100644
--- a/src/qml/UI.qml
+++ b/src/qml/UI.qml
@@ -64,8 +64,7 @@ Item {
             }
 
             function showRoom(userId, category, roomId) {
-                var info = rooms.getWhere({userId, roomId, category}, 1)[0]
-
+                let info = rooms.getWhere({userId, roomId, category}, 1)[0]
                 pageStack.replace("Chat/Chat.qml", {"roomInfo": info})
             }
 
diff --git a/src/qml/utils.js b/src/qml/utils.js
index 386ffd32..beeb0c2f 100644
--- a/src/qml/utils.js
+++ b/src/qml/utils.js
@@ -18,11 +18,11 @@ function hsla(hue, saturation, lightness, alpha=1.0) {
 function arrayToModelItem(keysName, array) {
     // Convert an array to an object suitable to be in a model, example:
     // [1, 2, 3] → [{keysName: 1}, {keysName: 2}, {keysName: 3}]
-    var items = []
+    let items = []
 
-    for (var i = 0; i < array.length; i++) {
-        var obj        = {}
-        obj[keysName] = array[i]
+    for (let item of array) {
+        let obj       = {}
+        obj[keysName] = item
         items.push(obj)
     }
     return items
@@ -31,8 +31,8 @@ function arrayToModelItem(keysName, array) {
 
 function hueFrom(string) {
     // Calculate and return a unique hue between 0 and 1 for the string
-    var hue = 0
-    for (var i = 0; i < string.length; i++) {
+    let hue = 0
+    for (let i = 0; i < string.length; i++) {
         hue += string.charCodeAt(i) * 99
     }
     return hue % 360 / 360
@@ -87,23 +87,16 @@ function translatedEventContent(ev) {
     if (ev.translatable == false) { return ev.content }
 
     // %S → sender display name
-    var name = users.find(ev.senderId).displayName
-    var text = ev.content.replace("%S", coloredNameHtml(name, ev.senderId))
+    let name = users.find(ev.senderId).displayName
+    let text = ev.content.replace("%S", coloredNameHtml(name, ev.senderId))
 
     // %T → target (event state_key) display name
     if (ev.targetUserId) {
-        var tname = users.find(ev.targetUserId).displayName
+        let tname = users.find(ev.targetUserId).displayName
         text = text.replace("%T", coloredNameHtml(tname, ev.targetUserId))
     }
 
-    text = qsTr(text)
-    if (ev.translatable == true) { return text }
-
-    // Else, model.translatable should be an array of args
-    for (var i = 0; ev.translatable.length; i++) {
-        text = text.arg(ev.translatable[i])
-    }
-    return text
+    return qsTr(text)
 }
 
 
@@ -111,10 +104,10 @@ function filterMatches(filter, text) {
     filter = filter.toLowerCase()
     text   = text.toLowerCase()
 
-    var words = filter.split(" ")
+    let words = filter.split(" ")
 
-    for (var i = 0; i < words.length; i++) {
-        if (words[i] && ! text.includes(words[i])) {
+    for (let word of words) {
+        if (word && ! text.includes(word)) {
             return false
         }
     }