Auto Sync
Two-way sync between local storage and Google Drive. Save to one, and the other is updated automatically.
What is Auto Sync?
Auto Sync automatically copies your file to the other storage location whenever you save.
Save to Cloud
Also saved locally
Save Locally
Also saved to cloud
No manual copying needed. Just save as usual, and both locations stay up to date.
Auto Sync is enabled by default. You can start using it without any special setup. When you save, your data is automatically saved to both local and the cloud, so this is now the standard save path. If you want to save locally only, turn off Auto Sync.
First-Time Setup
To use Auto Sync, you need two things:
- Connect to Google Drive
Connect your Google Drive from the Settings page. - Choose a local sync folder
When you save to the cloud and no local folder is set yet, a guide will automatically appear to help you choose one.Once you choose a folder, every future cloud save will also save a copy there automatically.
You can also set it manually by choosing a destination folder once via File > Save.
How Sync Works
Automatic Sync on Save
When you save a file, the following happens:
| Situation | Action |
|---|---|
| File doesn't exist on the other side | Automatically creates a copy |
| Both exist with same content | Nothing (already in sync) |
| Only one side updated since the last sync (typical case) | Mirrors to the other side automatically (no dialog) |
| Both sides updated independently | Shows a confirmation dialog |
| Previously synced file deleted from one side | Asks whether to re-save |
Most of the time you edit one side, save it, and the other side is still in the previously-synced state. Auto Sync mirrors silently in that case. You'll only see a dialog when both sides have been edited independently — the genuinely ambiguous "which one is correct?" case.
Synced Files Match Exactly
After sync, the local and Drive copies match across all of these:
- Content (byte-for-byte) — both sides written with UTF-8 BOM
- Modification time — Drive's
modifiedTimeis set to match the local file's mtime - Size — identical content means identical size
So when you open the file from a different device, there's no ambiguity about which copy is the right one.
When Contents Differ
Only when both sides were updated independently, you can choose:
- Yes — Overwrite the older version with the newer one (determined by modification time)
- Keep Both — Save the older version under a different name (_conflict_timestamp), then overwrite
- No — Skip syncing this time
Turning Auto Sync ON/OFF
- Open Settings from the top menu
- Select the "File" tab
- Toggle the "Auto Sync" checkbox ON or OFF
Cloud and local files may get out of sync. Remember to save to both locations manually.
Stop only the copy to this device's folder
The same File tab has a checkbox, "Also copy to a folder on this device when saving to Google Drive" (ON by default).
- When OFF, that device saves to Google Drive only. Saving to Google Drive works as before.
- The file in the device's folder stays as it was when you turned this OFF and is no longer updated.
- This setting is per device. For example, you can keep copying on your PC and stop it on your phone.
Use it when you want to stop the write-permission prompt on your phone (see "Asked for permission every time on a phone" below).
On a phone, turning Auto Sync OFF means Save no longer goes to the cloud; every save becomes a download to the device. If you want to keep using Google Drive, leave Auto Sync ON and turn off only this checkbox.
Asked for permission every time on a phone
When you save to Google Drive with Chrome for Android, you may see these prompts:
- Reading Forest's "Local Sync" dialog ([Allow], [Later], [Do not copy on this device])
- Then Chrome's own permission prompt to edit files
Your save to Google Drive has already completed at this point. The prompt asks for permission to update the copy in the device's folder.
Chrome on smartphones keeps this permission only until the tab is closed (Chrome's own prompt says so as well). So you are asked once, on your first save, each time you open the app. Later saves in the same session do not ask again. The browser decides how long the permission lasts; Reading Forest cannot extend it.
- Keep the copy on the device up to date — Tap [Allow], then tap Allow in Chrome's prompt as well.
- Google Drive is enough — Tap [Do not copy on this device]. The prompt will no longer appear. To undo, turn on the checkbox in "Stop only the copy to this device's folder" above.
- Skip this time — Tap [Later]. The copy on the device stays out of date, and you will be asked again the next time you open the app.
Notes
- Local sync requires the File System Access API. Available on desktop Chrome / Edge.
- On iPhone/iPad, Safari, or Firefox, local auto-sync is not available. Use cloud saving only.
- On Chrome for Android, you are asked for folder-writing permission once each time you open the app (Asked for permission every time on a phone).
- Cloud sync requires an internet connection.
- Sync happens at the time you save. It is not a continuous background sync.
FAQ
Yes. You can turn it OFF in Settings > File tab.
When you save to the cloud and no local folder is set, a guide will appear automatically. Just choose a folder and you're done.
You can also set it manually by choosing a destination folder once via File > Save.
A dialog will let you overwrite, keep both versions, or skip.
Local sync works on desktop Chrome/Edge and on Chrome for Android. It is not available on iPhone/iPad, Safari, or Firefox; use cloud saving there.
Chrome on smartphones keeps the folder-writing permission only until the tab is closed, so you are asked once, on your first save, each time you open the app. Tap [Do not copy on this device] in the dialog to save only to Google Drive on that device; the dialog will no longer appear. See Asked for permission every time on a phone for details.
Yes. With Auto Sync ON, the next time you save to the cloud, a guide will appear to help you choose a local folder. Once set, your file will be copied locally and all future saves will sync automatically.