diff --git a/client/src/utils/files.ts b/client/src/utils/files.ts
new file mode 100644
index 0000000..49c3171
--- /dev/null
+++ b/client/src/utils/files.ts
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2022 Savoir-faire Linux Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation; either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public
+ * License along with this program.  If not, see
+ * <https://www.gnu.org/licenses/>.
+ */
+
+export class FileHandler {
+  private static lastId = 0;
+
+  private static getNewId() {
+    return ++this.lastId;
+  }
+
+  readonly id: number;
+  readonly file: File;
+  readonly url: string;
+
+  constructor(file: File) {
+    this.id = FileHandler.getNewId();
+    this.file = file;
+    this.url = URL.createObjectURL(file);
+  }
+}
diff --git a/client/src/utils/units.ts b/client/src/utils/units.ts
new file mode 100644
index 0000000..553b66c
--- /dev/null
+++ b/client/src/utils/units.ts
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2022 Savoir-faire Linux Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation; either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public
+ * License along with this program.  If not, see
+ * <https://www.gnu.org/licenses/>.
+ */
+import { filesize } from 'filesize';
+import { useMemo } from 'react';
+import { useTranslation } from 'react-i18next';
+
+// 'filesize.js' library requires us to define the symbols ourselves for localization:
+// https://github.com/avoidwork/filesize.js/issues/64
+// https://github.com/avoidwork/filesize.js/issues/96
+// Could not find a library doing it by itself
+const dataSizeSymbols: Record<string, Record<string, string>> = {
+  fr: { B: 'o', kB: 'ko', MB: 'Mo', GB: 'Go', TB: 'To', PB: 'Po', EB: 'Eo', ZB: 'Zo', YB: 'Yo' },
+  ru: { B: 'Б', kB: 'кБ', MB: 'МБ', GB: 'ГБ', TB: 'ТБ', PB: 'ПБ', EB: 'ЭБ', ZB: 'ЗБ', YB: 'ЙБ' },
+  default: { B: 'B', kB: 'kB', MB: 'MB', GB: 'GB', TB: 'TB', PB: 'PB', EB: 'EB', ZB: 'ZB', YB: 'YB' },
+};
+
+export const useDataSizeUnits = (nbBytes: number) => {
+  const { i18n } = useTranslation();
+  return useMemo(() => {
+    const options = {
+      symbols: dataSizeSymbols[i18n.language] || dataSizeSymbols['default'], // undefined is not supported
+      locale: i18n.language,
+    };
+    return filesize(nbBytes, options);
+  }, [i18n, nbBytes]);
+};