---
title: "Backing up and restoring"
description: "Back up all your Mimir notes to one file on a Mac, and restore them from that file."
---

A backup is a copy of all your notes in one file. On a Mac, Mimir makes the
copy for you and can put it back. With Cloud Sync on, that backup includes
the notes you write on iPhone and iPad.

## Backing up your notes

1. Choose **File** > **Back Up Notes…** in the menu bar.
2. Choose where to save the copy.

Mimir names the copy with today's date, for example
`mimir-backup-2026-10-11.db`. It doesn't
save the copy in the folder that holds your notes.

:::warning
Don't copy `mimir.db` in Finder or with `cp` while Mimir is running. Mimir
keeps your most recent edits in a second file next to the database until it
writes them in, so a plain copy can leave out your latest notes.
:::

Time Machine and other backup tools copy the file while Mimir runs. Quit
Mimir before the backup tool starts, or let the tool back up a copy made
with **Back Up Notes…**.

[Exporting your notes](/exporting-your-notes) is safe while Mimir runs,
but it isn't a backup Mimir can restore.

## Restoring a backup

1. Choose **File** > **Restore from Backup…** in the menu bar.
2. Choose your backup file.
3. Read the warning, then choose **Replace My Notes**.

Mimir restarts with the notes from the backup. Mimir keeps a copy of your notes from
before the restore, named `mimir-before-restore.db`, in the folder that
holds `mimir.db`.

### With Cloud Sync on

With Cloud Sync on, Mimir can't restore a backup, because Cloud Sync would
bring back everything written after the backup. Instead,
**Restore from Backup…** shows the steps below, with an **Open Cloud Sync**
button for the first one. To restore, start Cloud Sync over.

:::warning
Your other devices still have everything written after the backup. If you
add one without emptying it first, it brings those notes back into Cloud
Sync, and from there to every device.
:::

1. [Erase your synced notes](/sync-across-devices#erasing-your-synced-notes).
    Your eight words stop working.

2. Choose **File** > **Restore from Backup…** again and restore the
    backup.

3. [Turn on Cloud Sync](/sync-across-devices#turning-on-cloud-sync) with
    the same license key. You get new eight words.

4. Empty each of your other devices.

    **Mac**

    1. Quit Mimir.
    2. In Finder, choose **Go** > **Go to Folder…** and enter
       `~/Library/Application Support`.
    3. Move the `mimir` folder to the Trash. It holds the database and the
       files Mimir keeps next to it.
    4. Open Mimir. It starts with no notes.

    **iPhone and iPad**

    Delete Mimir from the device and install it again.

5. [Add each device](/sync-across-devices#adding-another-device) with the
    new eight words. It gets the notes from the backup.

### If Mimir doesn't open

Without Cloud Sync, you can put a backup back by hand:

1. Open the folder described in
   [Where your notes live](/where-your-notes-live).
2. Delete `mimir.db-wal` and `mimir.db-shm`, if they're there. They belong
   to the current database and can damage the backup you put in its place.
3. Replace `mimir.db` with your backup copy. Rename the copy to `mimir.db`
   if it has a different name.
4. Open Mimir.

:::warning
With Cloud Sync on, don't put a backup back by hand. Mimir reconnects as it
opens and brings back every change made since the backup. Email
[support@justmimir.com](mailto:support@justmimir.com) instead.
:::