diff --git a/src/components/appSelectPeers.ts b/src/components/appSelectPeers.ts
index 7b1a7efa..5377669f 100644
--- a/src/components/appSelectPeers.ts
+++ b/src/components/appSelectPeers.ts
@@ -10,6 +10,7 @@ import Scrollable from "./scrollable";
 import { FocusDirection } from "../helpers/fastSmoothScroll";
 import CheckboxField from "./checkboxField";
 import appProfileManager from "../lib/appManagers/appProfileManager";
+import { safeAssign } from "../helpers/object";
 
 type PeerType = 'contacts' | 'dialogs' | 'channelParticipants';
 
@@ -69,7 +70,7 @@ export default class AppSelectPeers {
     rippleEnabled?: boolean,
     avatarSize?: AppSelectPeers['avatarSize'],
   }) {
-    Object.assign(this, options);
+    safeAssign(this, options);
 
     this.container.classList.add('selector');
 
@@ -440,7 +441,7 @@ export default class AppSelectPeers {
     });
   }
 
-  public add(peerId: any, title?: string, scroll = true) {
+  public add(peerId: any, title?: string | HTMLElement, scroll = true) {
     //console.trace('add');
     this.selected.add(peerId);
 
@@ -467,7 +468,12 @@ export default class AppSelectPeers {
     }
 
     if(title) {
-      div.innerHTML = title;
+      if(typeof(title) === 'string') {
+        div.innerHTML = title;
+      } else {
+        div.innerHTML = '';
+        div.append(title);
+      }
     }
 
     div.insertAdjacentElement('afterbegin', avatarEl);
diff --git a/src/components/editPeer.ts b/src/components/editPeer.ts
index 9d008f4c..882ff66e 100644
--- a/src/components/editPeer.ts
+++ b/src/components/editPeer.ts
@@ -4,6 +4,7 @@ import AvatarElement from "./avatar";
 import InputField from "./inputField";
 import ListenerSetter from "../helpers/listenerSetter";
 import Button from "./button";
+import { safeAssign } from "../helpers/object";
 
 export default class EditPeer {
   public nextBtn: HTMLButtonElement;
@@ -23,7 +24,7 @@ export default class EditPeer {
     listenerSetter: ListenerSetter,
     doNotEditAvatar?: boolean,
   }) {
-    Object.assign(this, options);
+    safeAssign(this, options);
 
     this.nextBtn = Button('btn-circle btn-corner tgico-check');
 
diff --git a/src/components/inputField.ts b/src/components/inputField.ts
index fceef259..dc454d37 100644
--- a/src/components/inputField.ts
+++ b/src/components/inputField.ts
@@ -1,7 +1,7 @@
 import { getRichValue, isInputEmpty } from "../helpers/dom";
 import { debounce } from "../helpers/schedulers";
 import { checkRTL } from "../helpers/string";
-import { i18n_, LangPackKey } from "../lib/langPack";
+import { i18n, LangPackKey } from "../lib/langPack";
 import RichTextProcessor from "../lib/richtextprocessor";
 
 let init = () => {
@@ -143,7 +143,7 @@ class InputField {
 
     if(label) {
       this.label = document.createElement('label');
-      i18n_({element: this.label, key: label});
+      this.label.append(i18n(label));
       this.container.append(this.label);
     }
 
@@ -234,9 +234,10 @@ class InputField {
     }
   }
 
-  public setState(state: InputState, label?: string) {
+  public setState(state: InputState, label?: LangPackKey) {
     if(label) {
-      this.label.innerHTML = label;
+      this.label.innerHTML = '';
+      this.label.append(i18n(label));
     }
 
     this.input.classList.toggle('error', !!(state & InputState.Error));
diff --git a/src/components/preloader.ts b/src/components/preloader.ts
index f7a0a01e..b17fa185 100644
--- a/src/components/preloader.ts
+++ b/src/components/preloader.ts
@@ -2,6 +2,7 @@ import { isInDOM, cancelEvent, attachClickEvent } from "../helpers/dom";
 import { CancellablePromise } from "../helpers/cancellablePromise";
 import SetTransition from "./singleTransition";
 import { fastRaf } from "../helpers/schedulers";
+import { safeAssign } from "../helpers/object";
 
 const TRANSITION_TIME = 200;
 
@@ -34,7 +35,7 @@ export default class ProgressivePreloader {
     attachMethod: ProgressivePreloader['attachMethod']
   }>) {
     if(options) {
-      Object.assign(this, options);
+      safeAssign(this, options);
     }
   }
 
diff --git a/src/components/sidebarLeft/index.ts b/src/components/sidebarLeft/index.ts
index 2df87c85..a7d79d75 100644
--- a/src/components/sidebarLeft/index.ts
+++ b/src/components/sidebarLeft/index.ts
@@ -24,6 +24,8 @@ import AppContactsTab from "./tabs/contacts";
 import AppArchivedTab from "./tabs/archivedTab";
 import AppAddMembersTab from "./tabs/addMembers";
 import { i18n_, LangPackKey } from "../../lib/langPack";
+import ButtonMenuToggle from "../buttonMenuToggle";
+import ButtonMenu, { ButtonMenuItemOptions } from "../buttonMenu";
 
 export const LEFT_COLUMN_ACTIVE_CLASSNAME = 'is-left-column-shown';
 
@@ -34,14 +36,6 @@ export class AppSidebarLeft extends SidebarSlider {
   private inputSearch: InputSearch;
   
   private menuEl: HTMLElement;
-  private buttons: {
-    newGroup: HTMLButtonElement,
-    contacts: HTMLButtonElement,
-    archived: HTMLButtonElement,
-    saved: HTMLButtonElement,
-    settings: HTMLButtonElement,
-    help: HTMLButtonElement
-  } = {} as any;
   public archivedCount: HTMLSpanElement;
 
   private newBtnMenu: HTMLElement;
@@ -68,58 +62,87 @@ export class AppSidebarLeft extends SidebarSlider {
     const sidebarHeader = this.sidebarEl.querySelector('.item-main .sidebar-header');
     sidebarHeader.append(this.inputSearch.container);
 
+    const onNewGroupClick = () => {
+      new AppAddMembersTab(this).open({
+        peerId: 0,
+        type: 'chat',
+        skippable: false,
+        takeOut: (peerIds) => {
+          new AppNewGroupTab(this).open(peerIds);
+        },
+        title: 'Add Members',
+        placeholder: 'Add People...'
+      });
+    };
+
+    const onContactsClick = () => {
+      new AppContactsTab(this).open();
+    };
+
     this.toolsBtn = this.sidebarEl.querySelector('.sidebar-tools-button') as HTMLButtonElement;
     this.backBtn = this.sidebarEl.querySelector('.sidebar-back-button') as HTMLButtonElement;
 
+    const btnArchive: ButtonMenuItemOptions = {
+      icon: 'archive',
+      text: 'Archived',
+      onClick: () => {
+        new AppArchivedTab(this).open();
+      }
+    };
+
+    const btnMenu = ButtonMenu([{
+      icon: 'newgroup',
+      text: 'New Group',
+      onClick: onNewGroupClick
+    }, {
+      icon: 'user',
+      text: 'Contacts',
+      onClick: onContactsClick
+    }, btnArchive, {
+      icon: 'savedmessages',
+      text: 'Saved',
+      onClick: () => {
+        setTimeout(() => { // menu doesn't close if no timeout (lol)
+          appImManager.setPeer(appImManager.myId);
+        }, 0);
+      }
+    }, {
+      icon: 'settings',
+      text: 'Settings',
+      onClick: () => {
+        new AppSettingsTab(this).open();
+      }
+    }, {
+      icon: 'help btn-disabled',
+      text: 'Help',
+      onClick: () => {
+
+      }
+    }]);
+
+    btnMenu.classList.add('bottom-right');
+
+    this.toolsBtn.append(btnMenu);
+
     this.menuEl = this.toolsBtn.querySelector('.btn-menu');
     this.newBtnMenu = this.sidebarEl.querySelector('#new-menu');
 
     this.inputSearch.input.addEventListener('focus', () => this.initSearch(), {once: true});
 
-    parseMenuButtonsTo(this.buttons, this.menuEl.children);
     parseMenuButtonsTo(this.newButtons, this.newBtnMenu.firstElementChild.children);
 
-    this.archivedCount = this.buttons.archived.querySelector('.archived-count') as HTMLSpanElement;
-
-    attachClickEvent(this.buttons.saved, (e) => {
-      ///////this.log('savedbtn click');
-      setTimeout(() => { // menu doesn't close if no timeout (lol)
-        appImManager.setPeer(appImManager.myId);
-      }, 0);
-    });
-    
-    attachClickEvent(this.buttons.archived, (e) => {
-      new AppArchivedTab(this).open();
-    });
+    this.archivedCount = document.createElement('span');
+    this.archivedCount.className = 'archived-count badge badge-24 badge-gray';
 
-    [this.newButtons.privateChat, this.buttons.contacts].forEach(btn => {
-      attachClickEvent(btn, (e) => {
-        new AppContactsTab(this).open();
-      });
-    });
+    btnArchive.element.append(this.archivedCount);
 
-    attachClickEvent(this.buttons.settings, (e) => {
-      new AppSettingsTab(this).open();
-    });
+    attachClickEvent(this.newButtons.privateChat, onContactsClick);
 
     attachClickEvent(this.newButtons.channel, (e) => {
       new AppNewChannelTab(this).open();
     });
 
-    [this.newButtons.group, this.buttons.newGroup].forEach(btn => {
-      attachClickEvent(btn, (e) => {
-        new AppAddMembersTab(this).open({
-          peerId: 0,
-          type: 'chat',
-          skippable: false,
-          takeOut: (peerIds) => {
-            new AppNewGroupTab(this).open(peerIds);
-          },
-          title: 'Add Members',
-          placeholder: 'Add People...'
-        });
-      });
-    });
+    attachClickEvent(this.newButtons.group, onNewGroupClick);
 
     rootScope.on('dialogs_archived_unread', (e) => {
       this.archivedCount.innerText = '' + formatNumber(e.count, 1);
diff --git a/src/components/sidebarLeft/tabs/editFolder.ts b/src/components/sidebarLeft/tabs/editFolder.ts
index 1ec37b4b..2115c7c0 100644
--- a/src/components/sidebarLeft/tabs/editFolder.ts
+++ b/src/components/sidebarLeft/tabs/editFolder.ts
@@ -13,6 +13,7 @@ import ButtonMenuToggle from "../../buttonMenuToggle";
 import { ButtonMenuItemOptions } from "../../buttonMenu";
 import Button from "../../button";
 import AppIncludedChatsTab from "./includedChats";
+import { i18n, i18n_, LangPackKey } from "../../../lib/langPack";
 
 const MAX_FOLDER_NAME_LENGTH = 12;
 
@@ -38,7 +39,8 @@ export default class AppEditFolderTab extends SliderSuperTab {
     this.container.classList.add('edit-folder-container');
     this.caption = document.createElement('div');
     this.caption.classList.add('caption');
-    this.caption.innerHTML = `Choose chats and types of chats that will<br>appear and never appear in this folder.`;
+    this.caption.append(i18n(`Choose chats and types of chats that will
+appear and never appear in this folder.`));
     this.stickerContainer = document.createElement('div');
     this.stickerContainer.classList.add('sticker-container');
 
@@ -72,13 +74,13 @@ export default class AppEditFolderTab extends SliderSuperTab {
 
     inputWrapper.append(this.nameInputField.container);
 
-    const generateList = (className: string, h2Text: string, buttons: {icon: string, name?: string, withRipple?: true, text: string}[], to: any) => {
+    const generateList = (className: string, h2Text: LangPackKey, buttons: {icon: string, name?: string, withRipple?: true, text: string}[], to: any) => {
       const container = document.createElement('div');
       container.classList.add('folder-list', className);
 
       const h2 = document.createElement('div');
       h2.classList.add('sidebar-left-h2');
-      h2.innerHTML = h2Text;
+      i18n_({element: h2, key: h2Text});
 
       const categories = document.createElement('div');
       categories.classList.add('folder-categories');
@@ -102,46 +104,46 @@ export default class AppEditFolderTab extends SliderSuperTab {
       return container;
     };
 
-    this.include_peers = generateList('folder-list-included', 'Included chats', [{
+    this.include_peers = generateList('folder-list-included', 'ChatList.Filter.Include.Header', [{
       icon: 'add primary',
-      text: 'Add Chats',
+      text: 'ChatList.Filter.Include.AddChat',
       withRipple: true
     }, {
-      text: 'Contacts',
+      text: 'ChatList.Filter.Contacts',
       icon: 'newprivate',
       name: 'contacts'
     }, {
-      text: 'Non-Contacts',
+      text: 'ChatList.Filter.NonContacts',
       icon: 'noncontacts',
       name: 'non_contacts'
     }, {
-      text: 'Groups',
+      text: 'ChatList.Filter.Groups',
       icon: 'group',
       name: 'groups'
     }, {
-      text: 'Channels',
+      text: 'ChatList.Filter.Channels',
       icon: 'channel',
       name: 'broadcasts'
     }, {
-      text: 'Bots',
+      text: 'ChatList.Filter.Bots',
       icon: 'bots',
       name: 'bots'
     }], this.flags);
 
-    this.exclude_peers = generateList('folder-list-excluded', 'Excluded chats', [{
+    this.exclude_peers = generateList('folder-list-excluded', 'ChatList.Filter.Exclude.Header', [{
       icon: 'minus primary',
-      text: 'Remove Chats',
+      text: 'ChatList.Filter.Exclude.AddChat',
       withRipple: true
     }, {
-      text: 'Muted',
+      text: 'ChatList.Filter.MutedChats',
       icon: 'mute',
       name: 'exclude_muted'
     }, {
-      text: 'Archived',
+      text: 'ChatList.Filter.Archive',
       icon: 'archive',
       name: 'exclude_archived'
     }, {
-      text: 'Read',
+      text: 'ChatList.Filter.ReadChats',
       icon: 'readchats',
       name: 'exclude_read'
     }], this.flags);
@@ -225,7 +227,7 @@ export default class AppEditFolderTab extends SliderSuperTab {
 
   private onCreateOpen() {
     this.caption.style.display = '';
-    this.title.innerText = 'New Folder';
+    this.setTitle('New Folder');
     this.menuBtn.classList.add('hide');
     this.confirmBtn.classList.remove('hide');
     this.nameInputField.value = '';
@@ -238,7 +240,7 @@ export default class AppEditFolderTab extends SliderSuperTab {
 
   private onEditOpen() {
     this.caption.style.display = 'none';
-    this.title.innerText = this.type === 'create' ? 'New Folder' : 'Edit Folder';
+    this.setTitle(this.type === 'create' ? 'New Folder' : 'Edit Folder');
 
     if(this.type === 'edit') {
       this.menuBtn.classList.remove('hide');
diff --git a/src/components/sidebarLeft/tabs/editProfile.ts b/src/components/sidebarLeft/tabs/editProfile.ts
index d1a7b98b..02633838 100644
--- a/src/components/sidebarLeft/tabs/editProfile.ts
+++ b/src/components/sidebarLeft/tabs/editProfile.ts
@@ -5,7 +5,7 @@ import { SliderSuperTab } from "../../slider";
 import { attachClickEvent } from "../../../helpers/dom";
 import EditPeer from "../../editPeer";
 import { UsernameInputField } from "../../usernameInputField";
-import { i18n_ } from "../../../lib/langPack";
+import { i18n, i18n_ } from "../../../lib/langPack";
 
 // TODO: аватарка не поменяется в этой вкладке после изменения почему-то (если поставить в другом клиенте, и потом тут проверить, для этого ещё вышел в чатлист)
 
@@ -93,8 +93,21 @@ export default class AppEditProfileTab extends SliderSuperTab {
 
       const caption = document.createElement('div');
       caption.classList.add('caption');
-      caption.innerHTML = `You can choose a username on Telegram. If you do, other people will be able to find you by this username and contact you without knowing your phone number.<br><br>You can use a-z, 0-9 and underscores. Minimum length is 5 characters.<br><br><div class="profile-url-container">This link opens a chat with you:
-      <br><a class="profile-url" href="#" target="_blank"></a></div>`;
+      caption.append(i18n('UsernameSettings.ChangeDescription'));
+      caption.append(document.createElement('br'), document.createElement('br'));
+
+      const profileUrlContainer = this.profileUrlContainer = document.createElement('div');
+      profileUrlContainer.classList.add('profile-url-container');
+      profileUrlContainer.append(i18n('This link opens a chat with you:'));
+
+      const profileUrlAnchor = this.profileUrlAnchor = document.createElement('a');
+      profileUrlAnchor.classList.add('profile-url');
+      profileUrlAnchor.href = '#';
+      profileUrlAnchor.target = '_blank';
+
+      profileUrlContainer.append(profileUrlAnchor);
+
+      caption.append(profileUrlContainer);
 
       this.profileUrlContainer = caption.querySelector('.profile-url-container');
       this.profileUrlAnchor = this.profileUrlContainer.lastElementChild as HTMLAnchorElement;
diff --git a/src/components/sidebarLeft/tabs/includedChats.ts b/src/components/sidebarLeft/tabs/includedChats.ts
index b7eb226c..6f82cfeb 100644
--- a/src/components/sidebarLeft/tabs/includedChats.ts
+++ b/src/components/sidebarLeft/tabs/includedChats.ts
@@ -10,6 +10,7 @@ import ButtonIcon from "../../buttonIcon";
 import CheckboxField from "../../checkboxField";
 import Button from "../../button";
 import AppEditFolderTab from "./editFolder";
+import { i18n, LangPackKey, _i18n } from "../../../lib/langPack";
 
 export default class AppIncludedChatsTab extends SliderSuperTab {
   private editFolderTab: AppEditFolderTab;
@@ -123,7 +124,7 @@ export default class AppIncludedChatsTab extends SliderSuperTab {
       dom.containerEl.append(this.checkbox(selected));
       if(selected) dom.listEl.classList.add('active');
 
-      let subtitle = '';
+      let subtitle: LangPackKey;
 
       if(peerId > 0) {
         if(peerId === rootScope.myId) {
@@ -137,7 +138,7 @@ export default class AppIncludedChatsTab extends SliderSuperTab {
         subtitle = appPeersManager.isBroadcast(peerId) ? 'Channel' : 'Group';
       }
 
-      dom.lastMessageSpan.innerHTML = subtitle;
+      _i18n(dom.lastMessageSpan, subtitle);
     });
   };
 
@@ -148,14 +149,14 @@ export default class AppIncludedChatsTab extends SliderSuperTab {
     }
 
     this.confirmBtn.style.display = this.type === 'excluded' ? '' : 'none';
-    this.title.innerText = this.type === 'included' ? 'Included Chats' : 'Excluded Chats';
+    this.setTitle(this.type === 'included' ? 'Included Chats' : 'Excluded Chats');
 
     const filter = this.filter;
 
     const fragment = document.createDocumentFragment();
     const dd = document.createElement('div');
     dd.classList.add('sidebar-left-h2');
-    dd.innerText = 'Chat types';
+    _i18n(dd, 'ChatList.Add.TopSeparator');
     
     const categories = document.createElement('div');
     categories.classList.add('folder-categories');
@@ -163,17 +164,17 @@ export default class AppIncludedChatsTab extends SliderSuperTab {
     let details: {[flag: string]: {ico: string, text: string}};
     if(this.type === 'excluded') {
       details = {
-        exclude_muted: {ico: 'mute', text: 'Muted'},
-        exclude_archived: {ico: 'archive', text: 'Archived'},
-        exclude_read: {ico: 'readchats', text: 'Read'}
+        exclude_muted: {ico: 'mute', text: 'ChatList.Filter.MutedChats'},
+        exclude_archived: {ico: 'archive', text: 'ChatList.Filter.Archive'},
+        exclude_read: {ico: 'readchats', text: 'ChatList.Filter.ReadChats'}
       };
     } else {
       details = {
-        contacts: {ico: 'newprivate', text: 'Contacts'},
-        non_contacts: {ico: 'noncontacts', text: 'Non-Contacts'},
-        groups: {ico: 'group', text: 'Groups'},
-        broadcasts: {ico: 'newchannel', text: 'Channels'},
-        bots: {ico: 'bots', text: 'Bots'}
+        contacts: {ico: 'newprivate', text: 'ChatList.Filter.Contacts'},
+        non_contacts: {ico: 'noncontacts', text: 'ChatList.Filter.NonContacts'},
+        groups: {ico: 'group', text: 'ChatList.Filter.Groups'},
+        broadcasts: {ico: 'newchannel', text: 'ChatList.Filter.Channels'},
+        bots: {ico: 'bots', text: 'ChatList.Filter.Bots'}
       };
     }
 
@@ -191,7 +192,7 @@ export default class AppIncludedChatsTab extends SliderSuperTab {
 
     const d = document.createElement('div');
     d.classList.add('sidebar-left-h2');
-    d.innerText = 'Chats';
+    _i18n(d, 'ChatList.Add.BottomSeparator');
 
     fragment.append(dd, categories, hr, d);
 
@@ -210,7 +211,7 @@ export default class AppIncludedChatsTab extends SliderSuperTab {
 
     const _add = this.selector.add.bind(this.selector);
     this.selector.add = (peerId, title, scroll) => {
-      const div = _add(peerId, details[peerId]?.text, scroll);
+      const div = _add(peerId, details[peerId] ? i18n(details[peerId].text) : undefined, scroll);
       if(details[peerId]) {
         div.querySelector('avatar-element').classList.add('tgico-' + details[peerId].ico);
       }
@@ -256,4 +257,4 @@ export default class AppIncludedChatsTab extends SliderSuperTab {
     
     return super.open();
   }
-}
\ No newline at end of file
+}
diff --git a/src/components/sidebarLeft/tabs/language.ts b/src/components/sidebarLeft/tabs/language.ts
new file mode 100644
index 00000000..d687649c
--- /dev/null
+++ b/src/components/sidebarLeft/tabs/language.ts
@@ -0,0 +1,107 @@
+import { SettingSection } from "..";
+import { randomLong } from "../../../helpers/random";
+import I18n from "../../../lib/langPack";
+import RadioField from "../../radioField";
+import Row, { RadioFormFromRows } from "../../row";
+import { SliderSuperTab } from "../../slider"
+
+export default class AppLanguageTab extends SliderSuperTab {
+  protected init() {
+    this.container.classList.add('language-container');
+    this.setTitle('Telegram.LanguageViewController');
+
+    const section = new SettingSection({});
+
+    const radioRows: Map<string, Row> = new Map();
+
+    let r = [{
+      code: 'en',
+      text: 'English',
+      subtitle: 'English'
+    }, {
+      code: 'be',
+      text: 'Belarusian',
+      subtitle: 'Беларуская'
+    }, {
+      code: 'ca',
+      text: 'Catalan',
+      subtitle: 'Català'
+    }, {
+      code: 'nl',
+      text: 'Dutch',
+      subtitle: 'Nederlands'
+    }, {
+      code: 'fr',
+      text: 'French',
+      subtitle: 'Français'
+    }, {
+      code: 'de',
+      text: 'German',
+      subtitle: 'Deutsch'
+    }, {
+      code: 'it',
+      text: 'Italian',
+      subtitle: 'Italiano'
+    }, {
+      code: 'ms',
+      text: 'Malay',
+      subtitle: 'Bahasa Melayu'
+    }, {
+      code: 'pl',
+      text: 'Polish',
+      subtitle: 'Polski'
+    }, {
+      code: 'pt',
+      text: 'Portuguese (Brazil)',
+      subtitle: 'Português (Brasil)'
+    }, {
+      code: 'ru',
+      text: 'Russian',
+      subtitle: 'Русский'
+    }, {
+      code: 'es',
+      text: 'Spanish',
+      subtitle: 'Español'
+    }, {
+      code: 'tr',
+      text: 'Turkish',
+      subtitle: 'Türkçe'
+    }, {
+      code: 'uk',
+      text: 'Ukrainian',
+      subtitle: 'Українська'
+    }];
+
+    const random = randomLong();
+    r.forEach(({code, text, subtitle}) => {
+      const row = new Row({
+        radioField: new RadioField({
+          text, 
+          name: random, 
+          value: code
+        }),
+        subtitle
+      });
+      
+      radioRows.set(code, row);
+    });
+
+    const form = RadioFormFromRows([...radioRows.values()], (value) => {
+      I18n.getLangPack(value);
+    });
+
+    I18n.getCacheLangPack().then(langPack => {
+      const row = radioRows.get(langPack.lang_code);
+      if(!row) {
+        console.error('no row', row, langPack);
+        return;
+      }
+
+      row.radioField.setValueSilently(true);
+    });
+
+    section.content.append(form);
+    
+    this.scrollable.append(section.container);
+  }
+}
diff --git a/src/components/sidebarLeft/tabs/settings.ts b/src/components/sidebarLeft/tabs/settings.ts
index 221d32de..5abf1de6 100644
--- a/src/components/sidebarLeft/tabs/settings.ts
+++ b/src/components/sidebarLeft/tabs/settings.ts
@@ -10,6 +10,7 @@ import AppEditProfileTab from "./editProfile";
 import AppChatFoldersTab from "./chatFolders";
 import AppNotificationsTab from "./notifications";
 import PeerTitle from "../../peerTitle";
+import AppLanguageTab from "./language";
 //import AppMediaViewer from "../../appMediaViewerNew";
 
 export default class AppSettingsTab extends SliderSuperTab {
@@ -28,7 +29,7 @@ export default class AppSettingsTab extends SliderSuperTab {
 
   init() {
     this.container.classList.add('settings-container');
-    this.title.innerText = 'Settings';
+    this.setTitle('Settings');
     
     const btnMenu = ButtonMenuToggle({}, 'bottom-left', [{
       icon: 'logout',
@@ -130,6 +131,10 @@ export default class AppSettingsTab extends SliderSuperTab {
     this.buttons.privacy.addEventListener('click', () => {
       new AppPrivacyAndSecurityTab(this.slider).open();
     });
+
+    this.buttons.language.addEventListener('click', () => {
+      new AppLanguageTab(this.slider).open();
+    });
   }
 
   public fillElements() {
diff --git a/src/components/slider.ts b/src/components/slider.ts
index 31855a69..c84939fa 100644
--- a/src/components/slider.ts
+++ b/src/components/slider.ts
@@ -3,6 +3,7 @@ import { horizontalMenu } from "./horizontalMenu";
 import { TransitionSlider } from "./transition";
 import appNavigationController, { NavigationItem } from "./appNavigationController";
 import SliderSuperTab, { SliderSuperTabConstructable, SliderTab } from "./sliderTab";
+import { safeAssign } from "../helpers/object";
 
 const TRANSITION_TIME = 250;
 
@@ -24,7 +25,7 @@ export default class SidebarSlider {
     canHideFirst?: SidebarSlider['canHideFirst'],
     navigationType: SidebarSlider['navigationType']
   }) {
-    Object.assign(this, options);
+    safeAssign(this, options);
 
     if(!this.tabs) {
       this.tabs = new Map();
diff --git a/src/components/usernameInputField.ts b/src/components/usernameInputField.ts
index a2d0e8bc..c1fb8e73 100644
--- a/src/components/usernameInputField.ts
+++ b/src/components/usernameInputField.ts
@@ -1,6 +1,7 @@
 import ListenerSetter from "../helpers/listenerSetter";
 import { debounce } from "../helpers/schedulers";
 import appChatsManager from "../lib/appManagers/appChatsManager";
+import { LangPackKey } from "../lib/langPack";
 import apiManager from "../lib/mtproto/mtprotoworker";
 import RichTextProcessor from "../lib/richtextprocessor";
 import InputField, { InputFieldOptions, InputState } from "./inputField";
@@ -12,9 +13,9 @@ export class UsernameInputField extends InputField {
     peerId: number,
     listenerSetter: ListenerSetter,
     onChange?: () => void,
-    invalidText: string,
-    takenText: string,
-    availableText: string,
+    invalidText: LangPackKey,
+    takenText: LangPackKey,
+    availableText: LangPackKey,
     head?: string
   };
 
diff --git a/src/helpers/listLoader.ts b/src/helpers/listLoader.ts
index b938ea32..8196ef71 100644
--- a/src/helpers/listLoader.ts
+++ b/src/helpers/listLoader.ts
@@ -1,4 +1,5 @@
 import Scrollable from "../components/scrollable";
+import { safeAssign } from "./object";
 
 export default class ScrollableLoader {
   public loading = false;
@@ -11,7 +12,7 @@ export default class ScrollableLoader {
     scrollable: ScrollableLoader['scrollable'],
     getPromise: ScrollableLoader['getPromise']
   }) {
-    Object.assign(this, options);
+    safeAssign(this, options);
 
     options.scrollable.onScrolledBottom = () => {
       this.load();
diff --git a/src/helpers/object.ts b/src/helpers/object.ts
index f8396428..14e4d812 100644
--- a/src/helpers/object.ts
+++ b/src/helpers/object.ts
@@ -120,3 +120,13 @@ export function validateInitObject(initObject: any, currentObject: any) {
     }
   }
 }
+
+export function safeAssign(object: any, fromObject: any) {
+  if(!fromObject) return;
+  
+  for(let i in fromObject) {
+    if(fromObject[i] !== undefined) {
+      object[i] = fromObject[i];
+    }
+  }
+}
diff --git a/src/index.hbs b/src/index.hbs
index 3f75e662..9f2a406c 100644
--- a/src/index.hbs
+++ b/src/index.hbs
@@ -99,16 +99,7 @@
             <div class="sidebar-header">
               <div class="sidebar-header__btn-container">
                 <div class="animated-menu-icon"></div>
-                <div class="btn-icon btn-menu-toggle rp sidebar-tools-button is-visible">
-                  <div class="btn-menu bottom-right">
-                    <div class="btn-menu-item menu-newGroup tgico-newgroup rp">New Group</div>
-                    <div class="btn-menu-item menu-contacts tgico-user rp">Contacts</div>
-                    <div class="btn-menu-item menu-archived tgico-archive rp">Archived <span class="archived-count badge badge-24 badge-gray"></span></div>
-                    <div class="btn-menu-item menu-saved tgico-savedmessages rp">Saved</div>
-                    <div class="btn-menu-item menu-settings tgico-settings rp">Settings</div>
-                    <div class="btn-menu-item menu-help tgico-help rp btn-disabled">Help</div>
-                  </div>
-                </div>
+                <div class="btn-icon btn-menu-toggle rp sidebar-tools-button is-visible"></div>
                 <div class="btn-icon rp sidebar-back-button"></div>
               </div>
             </div>
diff --git a/src/lib/idb.ts b/src/lib/idb.ts
index c73d5c2a..e09b7e74 100644
--- a/src/lib/idb.ts
+++ b/src/lib/idb.ts
@@ -1,5 +1,6 @@
 import Database from '../config/database';
 import { blobConstruct } from '../helpers/blob';
+import { safeAssign } from '../helpers/object';
 import { logger } from './logger';
 
 /**
@@ -36,7 +37,7 @@ export default class IDBStorage {
   public storeName: string;
 
   constructor(options: IDBOptions) {
-    Object.assign(this, options);
+    safeAssign(this, options);
 
     this.openDatabase(true);
   }
diff --git a/src/lib/langPack.ts b/src/lib/langPack.ts
index 717df687..45e565bc 100644
--- a/src/lib/langPack.ts
+++ b/src/lib/langPack.ts
@@ -1,6 +1,8 @@
 import { MOUNT_CLASS_TO } from "../config/debug";
-import { LangPackString } from "../layer";
+import { safeAssign } from "../helpers/object";
+import { LangPackDifference, LangPackString } from "../layer";
 import apiManager from "./mtproto/mtprotoworker";
+import sessionStorage from "./sessionStorage";
 
 export const langPack: {[actionType: string]: string} = {
   "messageActionChatCreate": "created the group",
@@ -41,9 +43,15 @@ namespace Strings {
 
 	export type AccountSettings = 'AccountSettings.Filters' | 'AccountSettings.Notifications' | 'AccountSettings.PrivacyAndSecurity' | 'AccountSettings.Language' | 'AccountSettings.Bio';
 
-	export type Telegram = 'Telegram.GeneralSettingsViewController' | 'Telegram.NotificationSettingsViewController';
+	export type Telegram = 'Telegram.GeneralSettingsViewController' | 'Telegram.NotificationSettingsViewController' | 'Telegram.LanguageViewController';
 
-	export type ChatFilters = 'ChatList.Filter.Header' | 'ChatList.Filter.NewTitle' | 'ChatList.Filter.List.Header' | 'ChatList.Filter.Recommended.Header' | 'ChatList.Filter.Recommended.Add' | 'ChatList.Filter.List.Title';
+	export type ChatList = ChatListFilter;
+	export type ChatListAdd = 'ChatList.Add.TopSeparator' | 'ChatList.Add.BottomSeparator';
+	export type ChatListFilterIncluded = 'ChatList.Filter.Include.Header' | 'ChatList.Filter.Include.AddChat';
+	export type ChatListFilterExcluded = 'ChatList.Filter.Exclude.Header' | 'ChatList.Filter.Exclude.AddChat';
+	export type ChatListFilterList = 'ChatList.Filter.List.Header' | 'ChatList.Filter.List.Title';
+	export type ChatListFilterRecommended = 'ChatList.Filter.Recommended.Header' | 'ChatList.Filter.Recommended.Add';
+	export type ChatListFilter = ChatListAdd | ChatListFilterIncluded | ChatListFilterExcluded | ChatListFilterList | ChatListFilterRecommended | 'ChatList.Filter.Header' | 'ChatList.Filter.NewTitle' | 'ChatList.Filter.NonContacts' | 'ChatList.Filter.Contacts' | 'ChatList.Filter.Groups' | 'ChatList.Filter.Channels' | 'ChatList.Filter.Bots';
 
 	export type AutoDownloadSettings = 'AutoDownloadSettings.TypePrivateChats' | 'AutoDownloadSettings.TypeChannels';
 
@@ -51,37 +59,68 @@ namespace Strings {
 
 	export type Suggest = 'Suggest.Localization.Other';
 
-	export type LangPackKey = string | AccountSettings | EditAccount | Telegram | ChatFilters | LoginRegister | Bio | AutoDownloadSettings | DataAndStorage | Suggest;
+	export type UsernameSettings = 'UsernameSettings.ChangeDescription';
+
+	export type LangPackKey = string | AccountSettings | EditAccount | Telegram | ChatList | LoginRegister | Bio | AutoDownloadSettings | DataAndStorage | Suggest | UsernameSettings;
 }
 
 export type LangPackKey = Strings.LangPackKey;
 
 namespace I18n {
-	let strings: Partial<{[key in LangPackKey]: LangPackString}> = {};
+	export const strings: Map<LangPackKey, LangPackString> = new Map();
+
+	let lastRequestedLangCode: string;
+	export function getCacheLangPack(): Promise<LangPackDifference> {
+		return sessionStorage.get('langPack').then((langPack: LangPackDifference) => {
+			if(!langPack) {
+				return getLangPack('en');
+			}
+			
+			if(!lastRequestedLangCode) {
+				lastRequestedLangCode = langPack.lang_code;
+			}
+			
+			applyLangPack(langPack);
+			return langPack;
+		});
+	}
 
 	export function getLangPack(langCode: string) {
+		lastRequestedLangCode = langCode;
 		return apiManager.invokeApi('langpack.getLangPack', {
 			lang_code: langCode,
 			lang_pack: 'macos'
 		}).then(langPack => {
-			strings = {};
-			for(const string of langPack.strings) {
-				strings[string.key as LangPackKey] = string;
-			}
+			return sessionStorage.set({langPack}).then(() => {
+				applyLangPack(langPack);
+				return langPack;
+			});
+		});
+	}
+	
+	export function applyLangPack(langPack: LangPackDifference) {
+		if(langPack.lang_code !== lastRequestedLangCode) {
+			return;
+		}
 
-			const elements = Array.from(document.querySelectorAll(`.i18n`)) as HTMLElement[];
-			elements.forEach(element => {
-				const instance = weakMap.get(element);
+		strings.clear();
 
-				if(instance) {
-					instance.update();
-				}
-			});
+		for(const string of langPack.strings) {
+			strings.set(string.key as LangPackKey, string);
+		}
+
+		const elements = Array.from(document.querySelectorAll(`.i18n`)) as HTMLElement[];
+		elements.forEach(element => {
+			const instance = weakMap.get(element);
+
+			if(instance) {
+				instance.update();
+			}
 		});
 	}
 	
 	export function getString(key: LangPackKey, args?: any[]) {
-		const str = strings[key];
+		const str = strings.get(key);
 		let out = '';
 
 		if(str) {
@@ -103,7 +142,7 @@ namespace I18n {
 
 	export type IntlElementOptions = {
 		element?: HTMLElement,
-		property?: 'innerHTML' | 'placeholder'
+		property?: 'innerText' | 'innerHTML' | 'placeholder'
 		key: LangPackKey,
 		args?: any[]
 	};
@@ -111,7 +150,7 @@ namespace I18n {
 		public element: IntlElementOptions['element'];
 		public key: IntlElementOptions['key'];
 		public args: IntlElementOptions['args'];
-		public property: IntlElementOptions['property'] = 'innerHTML';
+		public property: IntlElementOptions['property'] = 'innerText';
 	
 		constructor(options: IntlElementOptions) {
 			this.element = options.element || document.createElement('span');
@@ -122,9 +161,7 @@ namespace I18n {
 		}
 	
 		public update(options?: IntlElementOptions) {
-			if(options) {
-				Object.assign(this, options);
-			}
+			safeAssign(this, options);
 	
 			(this.element as any)[this.property] = getString(this.key, this.args);
 		}
@@ -137,6 +174,10 @@ namespace I18n {
 	export function i18n_(options: IntlElementOptions) {
 		return new IntlElement(options).element;
 	}
+
+	export function _i18n(element: HTMLElement, key: LangPackKey, args?: any[], property?: IntlElementOptions['property']) {
+		return new IntlElement({element, key, args, property}).element;
+	}
 }
 
 export {I18n};
@@ -148,4 +189,7 @@ export {i18n};
 const i18n_ = I18n.i18n_;
 export {i18n_};
 
+const _i18n = I18n._i18n;
+export {_i18n};
+
 MOUNT_CLASS_TO && (MOUNT_CLASS_TO.I18n = I18n);
diff --git a/src/lib/sessionStorage.ts b/src/lib/sessionStorage.ts
index d5517773..b992aaae 100644
--- a/src/lib/sessionStorage.ts
+++ b/src/lib/sessionStorage.ts
@@ -1,4 +1,5 @@
 import { MOUNT_CLASS_TO } from '../config/debug';
+import { LangPackDifference } from '../layer';
 import type { State } from './appManagers/appStateManager';
 import AppStorage from './storage';
 
@@ -19,6 +20,7 @@ const sessionStorage = new AppStorage<{
       top: number
     }
   },
+  langPack: LangPackDifference
 } & State>({
   storeName: 'session'
 });
diff --git a/src/scss/partials/_leftSidebar.scss b/src/scss/partials/_leftSidebar.scss
index c5723f3e..69629b3d 100644
--- a/src/scss/partials/_leftSidebar.scss
+++ b/src/scss/partials/_leftSidebar.scss
@@ -569,7 +569,7 @@
     align-items: center;
     margin: 15px auto 1rem;
     border-radius: 30px;
-    padding: 0 12px;
+    padding: 0 24px 0 12px;
     display: flex;
   }
 
@@ -581,8 +581,9 @@
   .row {
     .btn-primary {
       height: 30px;
+      padding: 0 12px;
       font-size: 15px;
-      width: 52px;
+      width: auto;
       transition: width 0.2s;
       margin: 0;
       position: absolute;