diff --git a/filenames.auto.gni b/filenames.auto.gni
index 1b58bc2260c6..d8baa35249d6 100644
--- a/filenames.auto.gni
+++ b/filenames.auto.gni
@@ -196,7 +196,7 @@ auto_filenames = {
     "lib/browser/api/content-tracing.ts",
     "lib/browser/api/crash-reporter.ts",
     "lib/browser/api/desktop-capturer.ts",
-    "lib/browser/api/dialog.js",
+    "lib/browser/api/dialog.ts",
     "lib/browser/api/exports/electron.ts",
     "lib/browser/api/global-shortcut.ts",
     "lib/browser/api/in-app-purchase.ts",
diff --git a/lib/browser/api/dialog.js b/lib/browser/api/dialog.js
deleted file mode 100644
index 7f4685c47c9b..000000000000
--- a/lib/browser/api/dialog.js
+++ /dev/null
@@ -1,270 +0,0 @@
-'use strict';
-
-const { app, BrowserWindow, deprecate } = require('electron');
-const binding = process._linkedBinding('electron_browser_dialog');
-const v8Util = process._linkedBinding('electron_common_v8_util');
-
-const DialogType = {
-  OPEN: 'OPEN',
-  SAVE: 'SAVE'
-};
-
-const saveFileDialogProperties = {
-  createDirectory: 1 << 0,
-  showHiddenFiles: 1 << 1,
-  treatPackageAsDirectory: 1 << 2,
-  showOverwriteConfirmation: 1 << 3,
-  dontAddToRecent: 1 << 4
-};
-
-const openFileDialogProperties = {
-  openFile: 1 << 0,
-  openDirectory: 1 << 1,
-  multiSelections: 1 << 2,
-  createDirectory: 1 << 3, // macOS
-  showHiddenFiles: 1 << 4,
-  promptToCreate: 1 << 5, // Windows
-  noResolveAliases: 1 << 6, // macOS
-  treatPackageAsDirectory: 1 << 7, // macOS
-  dontAddToRecent: 1 << 8 // Windows
-};
-
-const normalizeAccessKey = (text) => {
-  if (typeof text !== 'string') return text;
-
-  // macOS does not have access keys so remove single ampersands
-  // and replace double ampersands with a single ampersand
-  if (process.platform === 'darwin') {
-    return text.replace(/&(&?)/g, '$1');
-  }
-
-  // Linux uses a single underscore as an access key prefix so escape
-  // existing single underscores with a second underscore, replace double
-  // ampersands with a single ampersand, and replace a single ampersand with
-  // a single underscore
-  if (process.platform === 'linux') {
-    return text.replace(/_/g, '__').replace(/&(.?)/g, (match, after) => {
-      if (after === '&') return after;
-      return `_${after}`;
-    });
-  }
-
-  return text;
-};
-
-const checkAppInitialized = function () {
-  if (!app.isReady()) {
-    throw new Error('dialog module can only be used after app is ready');
-  }
-};
-
-const setupDialogProperties = (type, properties) => {
-  const dialogPropertiesTypes = (type === DialogType.OPEN) ? openFileDialogProperties : saveFileDialogProperties;
-  let dialogProperties = 0;
-  for (const prop in dialogPropertiesTypes) {
-    if (properties.includes(prop)) {
-      dialogProperties |= dialogPropertiesTypes[prop];
-    }
-  }
-
-  return dialogProperties;
-};
-
-const saveDialog = (sync, window, options) => {
-  checkAppInitialized();
-
-  if (window && window.constructor !== BrowserWindow) {
-    options = window;
-    window = null;
-  }
-
-  if (options == null) options = { title: 'Save' };
-
-  const {
-    buttonLabel = '',
-    defaultPath = '',
-    filters = [],
-    properties = [],
-    title = '',
-    message = '',
-    securityScopedBookmarks = false,
-    nameFieldLabel = '',
-    showsTagField = true
-  } = options;
-
-  if (typeof title !== 'string') throw new TypeError('Title must be a string');
-  if (typeof buttonLabel !== 'string') throw new TypeError('Button label must be a string');
-  if (typeof defaultPath !== 'string') throw new TypeError('Default path must be a string');
-  if (typeof message !== 'string') throw new TypeError('Message must be a string');
-  if (typeof nameFieldLabel !== 'string') throw new TypeError('Name field label must be a string');
-
-  const settings = { buttonLabel, defaultPath, filters, title, message, securityScopedBookmarks, nameFieldLabel, showsTagField, window };
-  settings.properties = setupDialogProperties(DialogType.SAVE, properties);
-
-  return (sync) ? binding.showSaveDialogSync(settings) : binding.showSaveDialog(settings);
-};
-
-const openDialog = (sync, window, options) => {
-  checkAppInitialized();
-
-  if (window && window.constructor !== BrowserWindow) {
-    options = window;
-    window = null;
-  }
-
-  if (options == null) {
-    options = {
-      title: 'Open',
-      properties: ['openFile']
-    };
-  }
-
-  const {
-    buttonLabel = '',
-    defaultPath = '',
-    filters = [],
-    properties = ['openFile'],
-    title = '',
-    message = '',
-    securityScopedBookmarks = false
-  } = options;
-
-  if (!Array.isArray(properties)) throw new TypeError('Properties must be an array');
-
-  if (typeof title !== 'string') throw new TypeError('Title must be a string');
-  if (typeof buttonLabel !== 'string') throw new TypeError('Button label must be a string');
-  if (typeof defaultPath !== 'string') throw new TypeError('Default path must be a string');
-  if (typeof message !== 'string') throw new TypeError('Message must be a string');
-
-  const settings = { title, buttonLabel, defaultPath, filters, message, securityScopedBookmarks, window };
-  settings.properties = setupDialogProperties(DialogType.OPEN, properties);
-
-  return (sync) ? binding.showOpenDialogSync(settings) : binding.showOpenDialog(settings);
-};
-
-const messageBox = (sync, window, options) => {
-  checkAppInitialized();
-
-  if (window && window.constructor !== BrowserWindow) {
-    options = window;
-    window = null;
-  }
-
-  if (options == null) options = { type: 'none' };
-
-  const messageBoxTypes = ['none', 'info', 'warning', 'error', 'question'];
-  const messageBoxOptions = { noLink: 1 << 0 };
-
-  let {
-    buttons = [],
-    cancelId,
-    checkboxLabel = '',
-    checkboxChecked,
-    defaultId = -1,
-    detail = '',
-    icon = null,
-    noLink = false,
-    message = '',
-    title = '',
-    type = 'none'
-  } = options;
-
-  const messageBoxType = messageBoxTypes.indexOf(type);
-  if (messageBoxType === -1) throw new TypeError('Invalid message box type');
-  if (!Array.isArray(buttons)) throw new TypeError('Buttons must be an array');
-  if (options.normalizeAccessKeys) buttons = buttons.map(normalizeAccessKey);
-  if (typeof title !== 'string') throw new TypeError('Title must be a string');
-  if (typeof noLink !== 'boolean') throw new TypeError('noLink must be a boolean');
-  if (typeof message !== 'string') throw new TypeError('Message must be a string');
-  if (typeof detail !== 'string') throw new TypeError('Detail must be a string');
-  if (typeof checkboxLabel !== 'string') throw new TypeError('checkboxLabel must be a string');
-
-  checkboxChecked = !!checkboxChecked;
-  if (checkboxChecked && !checkboxLabel) {
-    throw new Error('checkboxChecked requires that checkboxLabel also be passed');
-  }
-
-  // Choose a default button to get selected when dialog is cancelled.
-  if (cancelId == null) {
-    // If the defaultId is set to 0, ensure the cancel button is a different index (1)
-    cancelId = (defaultId === 0 && buttons.length > 1) ? 1 : 0;
-    for (let i = 0; i < buttons.length; i++) {
-      const text = buttons[i].toLowerCase();
-      if (text === 'cancel' || text === 'no') {
-        cancelId = i;
-        break;
-      }
-    }
-  }
-
-  const settings = {
-    window,
-    messageBoxType,
-    buttons,
-    defaultId,
-    cancelId,
-    noLink,
-    title,
-    message,
-    detail,
-    checkboxLabel,
-    checkboxChecked,
-    icon
-  };
-
-  if (sync) {
-    return binding.showMessageBoxSync(settings);
-  } else {
-    return binding.showMessageBox(settings);
-  }
-};
-
-module.exports = {
-  showOpenDialog: function (window, options) {
-    return openDialog(false, window, options);
-  },
-
-  showOpenDialogSync: function (window, options) {
-    return openDialog(true, window, options);
-  },
-
-  showSaveDialog: function (window, options) {
-    return saveDialog(false, window, options);
-  },
-
-  showSaveDialogSync: function (window, options) {
-    return saveDialog(true, window, options);
-  },
-
-  showMessageBox: function (window, options) {
-    return messageBox(false, window, options);
-  },
-
-  showMessageBoxSync: function (window, options) {
-    return messageBox(true, window, options);
-  },
-
-  showErrorBox: function (...args) {
-    return binding.showErrorBox(...args);
-  },
-
-  showCertificateTrustDialog: function (window, options) {
-    if (window && window.constructor !== BrowserWindow) {
-      options = window;
-      window = null;
-    }
-
-    if (options == null || typeof options !== 'object') {
-      throw new TypeError('options must be an object');
-    }
-
-    const { certificate, message = '' } = options;
-    if (certificate == null || typeof certificate !== 'object') {
-      throw new TypeError('certificate must be an object');
-    }
-
-    if (typeof message !== 'string') throw new TypeError('message must be a string');
-
-    return binding.showCertificateTrustDialog(window, certificate, message);
-  }
-};
diff --git a/lib/browser/api/dialog.ts b/lib/browser/api/dialog.ts
new file mode 100644
index 000000000000..37bd7177c1a9
--- /dev/null
+++ b/lib/browser/api/dialog.ts
@@ -0,0 +1,306 @@
+import { app, BrowserWindow } from 'electron';
+import { OpenDialogOptions, OpenDialogReturnValue, MessageBoxOptions, SaveDialogOptions, SaveDialogReturnValue, MessageBoxReturnValue, CertificateTrustDialogOptions } from 'electron/main';
+const dialogBinding = process._linkedBinding('electron_browser_dialog');
+
+const DialogType = {
+  OPEN: 'OPEN' as 'OPEN',
+  SAVE: 'SAVE' as 'SAVE'
+};
+
+enum SaveFileDialogProperties {
+  createDirectory = 1 << 0,
+  showHiddenFiles = 1 << 1,
+  treatPackageAsDirectory = 1 << 2,
+  showOverwriteConfirmation = 1 << 3,
+  dontAddToRecent = 1 << 4
+}
+
+enum OpenFileDialogProperties {
+  openFile = 1 << 0,
+  openDirectory = 1 << 1,
+  multiSelections = 1 << 2,
+  createDirectory = 1 << 3, // macOS
+  showHiddenFiles = 1 << 4,
+  promptToCreate = 1 << 5, // Windows
+  noResolveAliases = 1 << 6, // macOS
+  treatPackageAsDirectory = 1 << 7, // macOS
+  dontAddToRecent = 1 << 8 // Windows
+}
+
+const normalizeAccessKey = (text: string) => {
+  if (typeof text !== 'string') return text;
+
+  // macOS does not have access keys so remove single ampersands
+  // and replace double ampersands with a single ampersand
+  if (process.platform === 'darwin') {
+    return text.replace(/&(&?)/g, '$1');
+  }
+
+  // Linux uses a single underscore as an access key prefix so escape
+  // existing single underscores with a second underscore, replace double
+  // ampersands with a single ampersand, and replace a single ampersand with
+  // a single underscore
+  if (process.platform === 'linux') {
+    return text.replace(/_/g, '__').replace(/&(.?)/g, (match, after) => {
+      if (after === '&') return after;
+      return `_${after}`;
+    });
+  }
+
+  return text;
+};
+
+const checkAppInitialized = function () {
+  if (!app.isReady()) {
+    throw new Error('dialog module can only be used after app is ready');
+  }
+};
+
+const setupOpenDialogProperties = (properties: (keyof typeof OpenFileDialogProperties)[]): number => {
+  let dialogProperties = 0;
+  for (const property of properties) {
+    if (Object.prototype.hasOwnProperty.call(OpenFileDialogProperties, property)) { dialogProperties |= OpenFileDialogProperties[property]; }
+  }
+  return dialogProperties;
+};
+
+const setupSaveDialogProperties = (properties: (keyof typeof SaveFileDialogProperties)[]): number => {
+  let dialogProperties = 0;
+  for (const property of properties) {
+    if (Object.prototype.hasOwnProperty.call(SaveFileDialogProperties, property)) { dialogProperties |= SaveFileDialogProperties[property]; }
+  }
+  return dialogProperties;
+};
+
+const setupDialogProperties = (type: keyof typeof DialogType, properties: string[]): number => {
+  if (type === DialogType.OPEN) {
+    return setupOpenDialogProperties(properties as (keyof typeof OpenFileDialogProperties)[]);
+  } else if (type === DialogType.SAVE) {
+    return setupSaveDialogProperties(properties as (keyof typeof SaveFileDialogProperties)[]);
+  } else {
+    return 0;
+  }
+};
+
+const saveDialog = (sync: boolean, window: BrowserWindow | null, options?: SaveDialogOptions) => {
+  checkAppInitialized();
+
+  if (options == null) options = { title: 'Save' };
+
+  const {
+    buttonLabel = '',
+    defaultPath = '',
+    filters = [],
+    properties = [],
+    title = '',
+    message = '',
+    securityScopedBookmarks = false,
+    nameFieldLabel = '',
+    showsTagField = true
+  } = options;
+
+  if (typeof title !== 'string') throw new TypeError('Title must be a string');
+  if (typeof buttonLabel !== 'string') throw new TypeError('Button label must be a string');
+  if (typeof defaultPath !== 'string') throw new TypeError('Default path must be a string');
+  if (typeof message !== 'string') throw new TypeError('Message must be a string');
+  if (typeof nameFieldLabel !== 'string') throw new TypeError('Name field label must be a string');
+
+  const settings = {
+    buttonLabel,
+    defaultPath,
+    filters,
+    title,
+    message,
+    securityScopedBookmarks,
+    nameFieldLabel,
+    showsTagField,
+    window,
+    properties: setupDialogProperties(DialogType.SAVE, properties)
+  };
+
+  return sync ? dialogBinding.showSaveDialogSync(settings) : dialogBinding.showSaveDialog(settings);
+};
+
+const openDialog = (sync: boolean, window: BrowserWindow | null, options?: OpenDialogOptions) => {
+  checkAppInitialized();
+
+  if (options == null) {
+    options = {
+      title: 'Open',
+      properties: ['openFile']
+    };
+  }
+
+  const {
+    buttonLabel = '',
+    defaultPath = '',
+    filters = [],
+    properties = ['openFile'],
+    title = '',
+    message = '',
+    securityScopedBookmarks = false
+  } = options;
+
+  if (!Array.isArray(properties)) throw new TypeError('Properties must be an array');
+
+  if (typeof title !== 'string') throw new TypeError('Title must be a string');
+  if (typeof buttonLabel !== 'string') throw new TypeError('Button label must be a string');
+  if (typeof defaultPath !== 'string') throw new TypeError('Default path must be a string');
+  if (typeof message !== 'string') throw new TypeError('Message must be a string');
+
+  const settings = {
+    title,
+    buttonLabel,
+    defaultPath,
+    filters,
+    message,
+    securityScopedBookmarks,
+    window,
+    properties: setupDialogProperties(DialogType.OPEN, properties)
+  };
+
+  return (sync) ? dialogBinding.showOpenDialogSync(settings) : dialogBinding.showOpenDialog(settings);
+};
+
+const messageBox = (sync: boolean, window: BrowserWindow | null, options?: MessageBoxOptions) => {
+  checkAppInitialized();
+
+  if (options == null) options = { type: 'none', message: '' };
+
+  const messageBoxTypes = ['none', 'info', 'warning', 'error', 'question'];
+
+  let {
+    buttons = [],
+    cancelId,
+    checkboxLabel = '',
+    checkboxChecked,
+    defaultId = -1,
+    detail = '',
+    icon = null,
+    noLink = false,
+    message = '',
+    title = '',
+    type = 'none'
+  } = options;
+
+  const messageBoxType = messageBoxTypes.indexOf(type);
+  if (messageBoxType === -1) throw new TypeError('Invalid message box type');
+  if (!Array.isArray(buttons)) throw new TypeError('Buttons must be an array');
+  if (options.normalizeAccessKeys) buttons = buttons.map(normalizeAccessKey);
+  if (typeof title !== 'string') throw new TypeError('Title must be a string');
+  if (typeof noLink !== 'boolean') throw new TypeError('noLink must be a boolean');
+  if (typeof message !== 'string') throw new TypeError('Message must be a string');
+  if (typeof detail !== 'string') throw new TypeError('Detail must be a string');
+  if (typeof checkboxLabel !== 'string') throw new TypeError('checkboxLabel must be a string');
+
+  checkboxChecked = !!checkboxChecked;
+  if (checkboxChecked && !checkboxLabel) {
+    throw new Error('checkboxChecked requires that checkboxLabel also be passed');
+  }
+
+  // Choose a default button to get selected when dialog is cancelled.
+  if (cancelId == null) {
+    // If the defaultId is set to 0, ensure the cancel button is a different index (1)
+    cancelId = (defaultId === 0 && buttons.length > 1) ? 1 : 0;
+    for (let i = 0; i < buttons.length; i++) {
+      const text = buttons[i].toLowerCase();
+      if (text === 'cancel' || text === 'no') {
+        cancelId = i;
+        break;
+      }
+    }
+  }
+
+  const settings = {
+    window,
+    messageBoxType,
+    buttons,
+    defaultId,
+    cancelId,
+    noLink,
+    title,
+    message,
+    detail,
+    checkboxLabel,
+    checkboxChecked,
+    icon
+  };
+
+  if (sync) {
+    return dialogBinding.showMessageBoxSync(settings);
+  } else {
+    return dialogBinding.showMessageBox(settings);
+  }
+};
+
+// eat dirt, eslint
+/* eslint-disable import/export */
+export function showOpenDialog(window: BrowserWindow, options: OpenDialogOptions): OpenDialogReturnValue;
+export function showOpenDialog(options: OpenDialogOptions): OpenDialogReturnValue;
+export function showOpenDialog (windowOrOptions: BrowserWindow | OpenDialogOptions, maybeOptions?: OpenDialogOptions): OpenDialogReturnValue {
+  const window = (windowOrOptions && !(windowOrOptions instanceof BrowserWindow) ? null : windowOrOptions);
+  const options = (windowOrOptions && !(windowOrOptions instanceof BrowserWindow) ? windowOrOptions : maybeOptions);
+  return openDialog(false, window, options);
+}
+
+export function showOpenDialogSync(window: BrowserWindow, options: OpenDialogOptions): OpenDialogReturnValue;
+export function showOpenDialogSync(options: OpenDialogOptions): OpenDialogReturnValue;
+export function showOpenDialogSync (windowOrOptions: BrowserWindow | OpenDialogOptions, maybeOptions?: OpenDialogOptions): OpenDialogReturnValue {
+  const window = (windowOrOptions && !(windowOrOptions instanceof BrowserWindow) ? null : windowOrOptions);
+  const options = (windowOrOptions && !(windowOrOptions instanceof BrowserWindow) ? windowOrOptions : maybeOptions);
+  return openDialog(true, window, options);
+}
+
+export function showSaveDialog(window: BrowserWindow, options: SaveDialogOptions): SaveDialogReturnValue;
+export function showSaveDialog(options: SaveDialogOptions): SaveDialogReturnValue;
+export function showSaveDialog (windowOrOptions: BrowserWindow | SaveDialogOptions, maybeOptions?: SaveDialogOptions): SaveDialogReturnValue {
+  const window = (windowOrOptions && !(windowOrOptions instanceof BrowserWindow) ? null : windowOrOptions);
+  const options = (windowOrOptions && !(windowOrOptions instanceof BrowserWindow) ? windowOrOptions : maybeOptions);
+  return saveDialog(false, window, options);
+}
+
+export function showSaveDialogSync(window: BrowserWindow, options: SaveDialogOptions): SaveDialogReturnValue;
+export function showSaveDialogSync(options: SaveDialogOptions): SaveDialogReturnValue;
+export function showSaveDialogSync (windowOrOptions: BrowserWindow | SaveDialogOptions, maybeOptions?: SaveDialogOptions): SaveDialogReturnValue {
+  const window = (windowOrOptions && !(windowOrOptions instanceof BrowserWindow) ? null : windowOrOptions);
+  const options = (windowOrOptions && !(windowOrOptions instanceof BrowserWindow) ? windowOrOptions : maybeOptions);
+  return saveDialog(true, window, options);
+}
+
+export function showMessageBox(window: BrowserWindow, options: MessageBoxOptions): MessageBoxReturnValue;
+export function showMessageBox(options: MessageBoxOptions): MessageBoxReturnValue;
+export function showMessageBox (windowOrOptions: BrowserWindow | MessageBoxOptions, maybeOptions?: MessageBoxOptions): MessageBoxReturnValue {
+  const window = (windowOrOptions && !(windowOrOptions instanceof BrowserWindow) ? null : windowOrOptions);
+  const options = (windowOrOptions && !(windowOrOptions instanceof BrowserWindow) ? windowOrOptions : maybeOptions);
+  return messageBox(false, window, options);
+}
+
+export function showMessageBoxSync(window: BrowserWindow, options: MessageBoxOptions): MessageBoxReturnValue;
+export function showMessageBoxSync(options: MessageBoxOptions): MessageBoxReturnValue;
+export function showMessageBoxSync (windowOrOptions: BrowserWindow | MessageBoxOptions, maybeOptions?: MessageBoxOptions): MessageBoxReturnValue {
+  const window = (windowOrOptions && !(windowOrOptions instanceof BrowserWindow) ? null : windowOrOptions);
+  const options = (windowOrOptions && !(windowOrOptions instanceof BrowserWindow) ? windowOrOptions : maybeOptions);
+  return messageBox(true, window, options);
+}
+
+export function showErrorBox (...args: any[]) {
+  return dialogBinding.showErrorBox(...args);
+}
+
+export function showCertificateTrustDialog (windowOrOptions: BrowserWindow | CertificateTrustDialogOptions, maybeOptions?: CertificateTrustDialogOptions) {
+  const window = (windowOrOptions && !(windowOrOptions instanceof BrowserWindow) ? null : windowOrOptions);
+  const options = (windowOrOptions && !(windowOrOptions instanceof BrowserWindow) ? windowOrOptions : maybeOptions);
+
+  if (options == null || typeof options !== 'object') {
+    throw new TypeError('options must be an object');
+  }
+
+  const { certificate, message = '' } = options;
+  if (certificate == null || typeof certificate !== 'object') {
+    throw new TypeError('certificate must be an object');
+  }
+
+  if (typeof message !== 'string') throw new TypeError('message must be a string');
+
+  return dialogBinding.showCertificateTrustDialog(window, certificate, message);
+}