Backups and restore behavior

A backup is a structured Yuhimo file that can be restored into the app.

It is designed to preserve your knowledge base, including pages and related learning data. Unlike a PDF or TXT export, a backup is meant for recovery and migration, not for reading outside Yuhimo.

Yuhimo supports three backup scopes. All use the same structured backup format designed for restore inside Yuhimo.

• Full workspace — your active pages, hierarchy, questions, and learning data for the workspace
• Single page — one page and its direct content (questions and learning data on that page when included)
• Subtree — a selected page branch, including child pages under that parent

Full workspace backup is available from Settings. Single-page and subtree backups are available from a page’s actions menu when you want a smaller recovery point.

Subtree backup is different from subtree export. Export creates readable HTML or TXT files in a ZIP. Backup creates a Yuhimo restore file.

Use backups when you want to preserve Yuhimo data in a form that can be restored later.

For example, you may create a backup before making large changes to your knowledge tree, or before moving data to another Yuhimo account or environment.

• Protecting against accidental data loss
• Saving a full copy of your knowledge base
• Preserving learning progress before major changes
• Recovering a previous copy of your notes
• Migration when supported by your setup

Depending on scope, a backup can include page content, page hierarchy, questions and answers, learning state, and review history for the pages in that backup.

This means a backup can preserve not only your text, but also the learning data connected to your pages.

Backups are stored as structured JSON files designed for Yuhimo restore, not as readable documents.

Backups do not necessarily include every temporary or account-level state.

Recently deleted pages in trash are separate from backup restore. Trash restore returns a deleted page; backup restore adds recovered copies.

• Pages in trash
• Temporary learning session state
• Account settings
• Browser-only cache
• External files or images stored only as links

Depending on your Yuhimo version, some temporary or account-level data may not be included. Offline mode keeps a read-only browser cache (about 20 MB per note, about 300 MB total). That cache is for access when offline — not backup and not included in backup files.

For recovery, use backups — not readable export. See Where your data is stored.

Embedded images and external resources are not copied into the backup file unless they are part of the page content Yuhimo stores.

Restore happens inside Yuhimo from Settings while you are online.

Choose Import backup (or the equivalent restore control), select your Yuhimo backup file, and confirm whether to preserve study state. Yuhimo validates the file, then adds restored pages as copies in your workspace.

Current exports use the latest backup format. Older backup files from earlier Yuhimo versions may still import when the structure is valid.

Restore adds imported pages as copies, instead of replacing your current workspace.

When you restore a backup, Yuhimo adds the restored data as new pages with new IDs. Your existing pages stay in place. Nothing is deleted or overwritten.

This makes restore safer because it avoids deleting or overwriting work you created after the backup. The tradeoff is that restoring the same backup more than once can create duplicates you may need to clean up manually.

See Trash and restore for recently deleted pages.

Yuhimo uses additive restore because it is safer.

A destructive restore could accidentally remove newer pages or overwrite changes you made after the backup was created. Adding restored data as copies avoids that risk.

The tradeoff is that you may need to clean up duplicates manually if you restore the same backup multiple times.

A backup may include learning state and review history for pages in the file. When you restore, Yuhimo asks whether to preserve study state.

If you turn on preserve study state, restored learning pages can keep scheduling data from the backup — such as due dates, stability, difficulty, and review history — on the new copied pages.

Preserve study state is off by default. When it is off, restored pages are added as copies without carrying over the old review schedule from the backup. Learning-enabled pages follow default learning behavior until you review them again online.

Preserve study state does not recover temporary session state, account settings, or data that was never in the backup file.

Either way, restored pages are new copies. Scheduling follows FSRS-light rules once learning is active on those pages.

Some backup files may contain structure that cannot be restored exactly as saved. Yuhimo repairs invalid data when possible instead of failing the whole restore.

• Orphaned pages — a page points to a parent that is missing from the backup may be moved to a safe root location
• Cycles in the tree — invalid parent/child loops may be broken so pages can be imported
• Broken embedded page references — links to pages outside the backup or invalid embeds may be removed or converted safely

After restore, Yuhimo may show warnings when some data could not be reproduced exactly — for example pages moved to root or embedded references dropped.

If restored pages appear in a different place than you expected, check whether warnings mentioned orphans or cycles. The content should still be available, but hierarchy may differ from the original backup.

Use backup when you want to restore data into Yuhimo later. Use import / export when you want a readable copy of your content outside Yuhimo.

Because restore adds copies, repeated restores can create duplicates.

Before restoring again, check whether the data is already present. If you restore a backup for recovery, review the restored pages and remove old or duplicate versions manually if needed.

Consider creating a fresh backup before large cleanup so you have a recovery point.

You create a full backup before reorganizing your knowledge tree.

Later, you decide you want to bring back the old version.

You restore the backup.

Yuhimo adds the backed-up pages as new copies. Your current pages remain untouched. You can compare both versions and decide what to keep.

A backup is not a full version-control system.

It helps you preserve and restore Yuhimo data, but it does not automatically merge changes or decide which duplicate page is the correct one.

• Version history for every small edit
• Automatic merge tools
• A replacement for readable exports
• A guarantee that external linked files are copied
• Instant full workspace replacement

For where data lives in normal use, see Where your data is stored.

Backups are for preserving and restoring Yuhimo data.

You can back up the full workspace, a single page, or a subtree. Restore adds copies instead of replacing your workspace. Optionally preserve study state on restore, and review warnings if Yuhimo repaired invalid structure.

For how your data relates to the app and portability, see Vendor lock-in.

Does restoring a backup delete my current pages?

No. Restoring a backup adds restored data as copies. It does not delete or overwrite your current pages.

Can restoring the same backup twice create duplicates?

Yes. Since restore is additive, restoring the same backup more than once can create duplicate pages.

How do I restore a backup file?

In Settings while online, use Import backup, choose your Yuhimo backup file, and confirm whether to preserve study state. Yuhimo adds restored pages as copies.

What backup scopes are available?

Full workspace, single page, and subtree. Full workspace is in Settings; single page and subtree are available from page actions.

Does a backup include learning progress?

Backups can include learning state and review history for pages in the file. On restore, you choose whether to preserve study state on the new copies.

Why did my review progress not restore?

You may have restored without preserve study state, the backup may not have included that page’s learning data, or restore warnings may have changed structure. Restored pages are always new copies.

Why did restored pages appear in a different place?

Yuhimo may move orphaned pages to root or break invalid cycles during restore. Check restore warnings for details.

Is backup the same as export?

No. Backup is for restoring data into Yuhimo. Export is for saving readable files like HTML, TXT, or PDF.

Can I use backup to move my knowledge base?

Yes. Backups are useful for recovery and migration when you want to bring Yuhimo data into another environment or account.

Does backup include external files or images?

Not if they are only stored as links. Yuhimo does not copy external resources into a backup unless they are part of the stored page content.