diff --git a/public/locales/en.json b/public/locales/en.json
index 3aea293..4fecf0d 100644
--- a/public/locales/en.json
+++ b/public/locales/en.json
@@ -571,5 +571,88 @@
   "apiErrorResult": {
     "resultUnknownTitle": "Unknown error",
     "resultUnknown": "See console for details."
+  },
+
+  "backups": {
+    "importButton": "Import backup",
+    "exportButton": "Export backup"
+  },
+
+  "import": {
+    "description": "Paste the backup code (or import from a file below) and enter the corresponding master password.",
+    "masterPasswordPlaceholder": "Master password",
+    "masterPasswordRequired": "Master password is required.",
+    "masterPasswordIncorrect": "Master password is incorrect.",
+    "fromFileButton": "Import from file",
+    "textareaPlaceholder": "Paste backup code here",
+    "modalButton": "Import",
+
+    "detectedFormat": "<0>Detected format:</0> <2 />",
+    "detectedFormatKristWebV1": "KristWeb v1",
+    "detectedFormatKristWebV2": "KristWeb v2",
+    "detectedFormatInvalid": "Invalid!",
+
+    "treeHeaderWallets": "Wallets",
+    "treeHeaderFriends": "Friends (Address Book)",
+
+    "treeWallet": "Wallet {{id}}",
+    "treeFriend": "Friend {{id}}",
+
+    "decodeErrors": {
+      "atob": "The backup could not be decoded as it is not valid base64!",
+      "json": "The backup could not be decoded as it is not valid JSON!",
+      "missingTester": "The backup could not be decoded as it is missing a tester key!",
+      "missingSalt": "The backup could not be decoded as it is missing a salt key!",
+      "invalidWallets": "The backup could not be decoded as the 'wallets' key is the wrong type!",
+      "invalidFriends": "The backup could not be decoded as the 'wallets' key is the wrong type!",
+      "unknown": "The backup could not be decoded due to an unknown error. See console for details."
+    },
+
+    "walletMessages": {
+      "success": "Wallet imported successfully.",
+      "successSkipped": "A wallet with the same address ({{address}}) and settings already exists, so it was skipped.",
+      "successUpdated": "A wallet with the same address ({{address}}) already exists. Its label was updated to \"{{label}}\"",
+      "successSkippedNoOverwrite": "A wallet with the same address ({{address}}) already exists, and you chose not to overwrite the label, so it was skipped.",
+
+      "warningSyncNode": "This wallet had a custom sync node, which is not supported in KristWeb v2. It was changed to the current sync node (<1 />).",
+      "warningIcon": "This wallet had a custom icon, which is not supported in KristWeb v2. It was skipped.",
+      "warningLabelInvalid": "The label for this wallet was invalid. It was skipped.",
+      "warningCategoryInvalid": "The label for this wallet was invalid. It was skipped.",
+
+      "errorDecrypt": "This wallet could not be decrypted!",
+      "errorPasswordDecrypt": "The password for this wallet could not be decrypted!",
+      "errorUnknownFormat": "This wallet uses an unknown or unsupported format!",
+      "errorFormatMissing": "This wallet is missing a format!",
+      "errorUsernameMissing": "This wallet is missing a username!",
+      "errorPasswordMissing": "This wallet is missing a password!",
+      "errorPrivateKeyMissing": "This wallet is missing a private key!",
+      "errorMasterKeyMissing": "This wallet is missing a master key!",
+      "errorLimitReached": "You reached the wallet limit. You currently cannot add any more wallets.",
+      "errorUnknown": "An unknown error occurred. See console for details."
+    },
+
+    "friendMessages": {
+      "errorNYI": "The Address Book has not yet been implemented, so it was skipped."
+    },
+
+    "results": {
+      "noneImported": "No new wallets were imported.",
+
+      "walletsImported": "<0>{{count, number}} new wallet</0> was imported.",
+      "walletsImported_plural": "<0>{{count, number}} new wallets</0> were imported.",
+      "walletsSkipped": "{{count, number}} wallet was skipped.",
+      "walletsSkipped_plural": "{{count, number}} wallets were skipped.",
+
+      "friendsImported": "<0>{{count, number}} new friend</0> was imported.",
+      "friendsImported_plural": "<0>{{count, number}} new friends</0> were imported.",
+      "friendsSkipped": "{{count, number}} friend was skipped.",
+      "friendsSkipped_plural": "{{count, number}} friends were skipped.",
+
+      "warnings": "There was <1>{{count, number}} warning</1> while importing your backup.",
+      "warnings_plural": "There were <1>{{count, number}} warning</1> while importing your backup.",
+      "errors": "There was <1>{{count, number}} error</1> while importing your backup.",
+      "errors_plural": "There were <1>{{count, number}} errors</1> while importing your backup.",
+      "errorsAndWarnings": "There were <1>{{errors, number}} error(s)</1> and <3>{{warnings, number}} warning(s)</3> while importing your backup."
+    }
   }
 }
diff --git a/src/global/AppRouter.tsx b/src/global/AppRouter.tsx
index 4223701..0f3af54 100644
--- a/src/global/AppRouter.tsx
+++ b/src/global/AppRouter.tsx
@@ -20,6 +20,8 @@
 
 import { CreditsPage } from "../pages/credits/CreditsPage";
 
+import { DevPage } from "../pages/dev/DevPage";
+
 import { NotFoundPage } from "../pages/NotFoundPage";
 
 interface AppRoute {
@@ -74,6 +76,9 @@
   { path: "/settings/debug/translations", name: "settings", component: <SettingsTranslations /> },
 
   { path: "/credits", name: "credits", component: <CreditsPage /> },
+
+  // TODO: remove this
+  { path: "/dev", name: "dev", component: <DevPage /> }
 ];
 
 export function AppRouter(): JSX.Element {
diff --git a/src/pages/backup/backupFormats.ts b/src/pages/backup/backupFormats.ts
new file mode 100644
index 0000000..d916029
--- /dev/null
+++ b/src/pages/backup/backupFormats.ts
@@ -0,0 +1,32 @@
+// Copyright (c) 2020-2021 Drew Lemmy
+// This file is part of KristWeb 2 under GPL-3.0.
+// Full details: https://github.com/tmpim/KristWeb2/blob/master/LICENSE.txt
+import { Wallet } from "../../krist/wallets/Wallet";
+
+// The values here are the translation keys for the formats.
+export enum BackupFormatType {
+  KRISTWEB_V1 = "import.detectedFormatKristWebV1",
+  KRISTWEB_V2 = "import.detectedFormatKristWebV2"
+}
+
+export interface BackupFormat {
+  // This value is inserted by `detectBackupFormat`.
+  type: BackupFormatType;
+
+  salt: string;
+  tester: string;
+}
+
+export interface BackupFormatKristWebV1 extends BackupFormat {
+  // KristWeb v1 backups contain a map of wallets, where the values are
+  // encrypted JSON.
+  wallets: Record<string, string>;
+  friends: Record<string, string>;
+}
+
+export interface BackupFormatKristWebV2 extends BackupFormat {
+  version: 2;
+
+  wallets: Record<string, Wallet>;
+  // friends: Record<string, Friend>;
+}
diff --git a/src/pages/backup/backupImport.tsx b/src/pages/backup/backupImport.tsx
new file mode 100644
index 0000000..a01e6e3
--- /dev/null
+++ b/src/pages/backup/backupImport.tsx
@@ -0,0 +1,63 @@
+// Copyright (c) 2020-2021 Drew Lemmy
+// This file is part of KristWeb 2 under GPL-3.0.
+// Full details: https://github.com/tmpim/KristWeb2/blob/master/LICENSE.txt
+import React from "react";
+
+import { aesGcmDecrypt } from "../../utils/crypto";
+import { decryptCryptoJS } from "../../utils/CryptoJS";
+
+import { BackupFormatType } from "./backupFormats";
+
+import Debug from "debug";
+const debug = Debug("kristweb:backup-import");
+
+export interface BackupResults {
+  newWallets: number;
+  skippedWallets: number;
+
+  messages: {
+    wallets: Record<string, BackupMessage[]>;
+    friends?: Record<string, BackupMessage[]>;
+  };
+}
+
+export interface BackupMessage {
+  type: "success" | "warning" | "error";
+  error?: Error;
+  message: React.ReactNode;
+}
+
+export class BackupError extends Error {
+  constructor(message: string) { super(message); }
+}
+
+/**
+ * Attempts to decrypt a given value using the appropriate function for the
+ * backup format, with the `masterPassword` as the password. Returns `false` if
+ * decryption failed for any reason.
+ */
+async function backupDecryptValue(
+  format: BackupFormatType,
+  masterPassword: string,
+  value: string
+): Promise<string | false> {
+  try {
+    switch (format) {
+    // KristWeb v1 used Crypto.JS for its cryptography (SubtleCrypto was not
+    // yet widespread enough), which uses its own funky key derivation
+    // algorithm. Use our polyfill for it.
+    // For more info, see `utils/CryptoJS.ts`.
+    case BackupFormatType.KRISTWEB_V1:
+      return decryptCryptoJS(value, masterPassword);
+
+    // KristWeb v2 simply uses WebCrypto/SubtleCrypto.
+    // For more info, see `utils/crypto.ts`.
+    case BackupFormatType.KRISTWEB_V2:
+      return aesGcmDecrypt(value, masterPassword);
+    }
+  } catch (err) {
+    debug("failed to decrypt backup value '%s'", value);
+    console.error(err);
+    return false;
+  }
+}
diff --git a/src/pages/backup/backupParser.ts b/src/pages/backup/backupParser.ts
new file mode 100644
index 0000000..39a9fc5
--- /dev/null
+++ b/src/pages/backup/backupParser.ts
@@ -0,0 +1,48 @@
+// Copyright (c) 2020-2021 Drew Lemmy
+// This file is part of KristWeb 2 under GPL-3.0.
+// Full details: https://github.com/tmpim/KristWeb2/blob/master/LICENSE.txt
+import {
+  BackupFormat, BackupFormatType,
+  BackupFormatKristWebV1, BackupFormatKristWebV2
+} from "./backupFormats";
+
+import { isPlainObject } from "lodash-es";
+
+export function detectBackupFormat(rawData: string): BackupFormat {
+  try {
+    // All backups are encoded as base64, so decode that first
+    const plainData = window.atob(rawData);
+
+    // Attempt to parse JSON
+    const data = JSON.parse(plainData);
+
+    // Check for required properties
+    if (!data.tester) throw new Error("import.decodeErrors.missingTester");
+    if (!data.salt) throw new Error("import.decodeErrors.missingSalt");
+    if (!isPlainObject(data.wallets))
+      throw new Error("import.decodeErrors.invalidWallets");
+    if (data.friends !== undefined && !isPlainObject(data.friends))
+      throw new Error("import.decodeErrors.invalidFriends");
+
+    // Determine the format
+    if (data.version === 2) {
+      // KristWeb v2
+      data.type = BackupFormatType.KRISTWEB_V2;
+      return data as BackupFormatKristWebV2;
+    } else {
+      // KristWeb v1
+      data.type = BackupFormatType.KRISTWEB_V1;
+      return data as BackupFormatKristWebV1;
+    }
+  } catch (err) {
+    // Invalid base64
+    if (err instanceof DOMException && err.name === "InvalidCharacterError")
+      throw new Error("import.decodeErrors.atob");
+
+    // Invalid json
+    if (err instanceof SyntaxError)
+      throw new Error("import.decodeErrors.json");
+
+    throw err;
+  }
+}
diff --git a/src/pages/dev/DevPage.tsx b/src/pages/dev/DevPage.tsx
new file mode 100644
index 0000000..530291a
--- /dev/null
+++ b/src/pages/dev/DevPage.tsx
@@ -0,0 +1,79 @@
+// Copyright (c) 2020-2021 Drew Lemmy
+// This file is part of KristWeb 2 under GPL-3.0.
+// Full details: https://github.com/tmpim/KristWeb2/blob/master/LICENSE.txt
+import React, { useState } from "react";
+import { Input, Button, Typography } from "antd";
+
+import { useTranslation, Trans } from "react-i18next";
+
+import { PageLayout } from "../../layout/PageLayout";
+
+import { BackupFormatType } from "../backup/backupFormats";
+import { detectBackupFormat } from "../backup/backupParser";
+
+const { TextArea } = Input;
+const { Text, Paragraph } = Typography;
+
+export function DevPage(): JSX.Element {
+  const { t } = useTranslation();
+
+  const [code, setCode] = useState("");
+  const [detectedFormatType, setDetectedFormatType] = useState<BackupFormatType>();
+  const [decodeError, setDecodeError] = useState<string | undefined>();
+
+  async function onImport() {
+    console.log(code);
+    try {
+      const format = detectBackupFormat(code);
+      setDecodeError(undefined);
+      setDetectedFormatType(format.type);
+    } catch (err) {
+      console.error(err);
+
+      const message = err.message // Translate the error if we can
+        ? err.message.startsWith("import.") ? t(err.message) : err.message
+        : t("import.decodeErrors.unknown");
+
+      setDecodeError(message);
+    }
+  }
+
+  // Display the detected format as a string, or "Invalid!" if there was an
+  // error decoding it.
+  function DetectFormatText(): JSX.Element | null {
+    if (decodeError) return <Text type="danger">{t("import.detectedFormatInvalid")}</Text>;
+    if (detectedFormatType) return <Text>{t(detectedFormatType)}</Text>;
+    return null;
+  }
+
+  return <PageLayout
+    title="Dev page"
+    siteTitle="Dev page"
+  >
+    {/* Detected format */}
+    {(detectedFormatType || decodeError) ? (
+      <Paragraph>
+        <Trans t={t} i18nKey="import.detectedFormat">
+          <b>Detected format:</b> <DetectFormatText />
+        </Trans>
+      </Paragraph>
+    ) : <></>}
+
+    {/* Decode error */}
+    {decodeError && <Paragraph type="danger">{decodeError}</Paragraph>}
+
+    {/* Backup code textarea */}
+    <TextArea
+      rows={4}
+      placeholder={t("import.textareaPlaceholder")}
+
+      value={code}
+      onChange={e => setCode(e.target.value)}
+    />
+
+    {/* Import button */}
+    <Button type="primary" onClick={onImport}>
+      {t("import.modalButton")}
+    </Button>
+  </PageLayout>;
+}