---
title: "One-way sync"
url: https://storagestudio.us/wiki/glossary-one-way-sync
category: "Glossary"
tags: ["glossary", "data transfers", "sync"]
summary: "One-way sync makes a destination an exact mirror of a source, including deleting files at the destination that aren't in the source."
updated: 2026-10-01T05:36:00.000Z
---

# One-way sync

One-way sync makes a destination an exact mirror of a source, including deleting files at the destination that aren't in the source.

**One-way sync** makes a destination an exact mirror of a source. New and changed files are copied across — and files at the destination that aren't in the source are **deleted**. Changes made at the destination never flow back.

In Data Transfers this is the **Sync (one-way)** operation: *"Make destination mirror source. Files in destination but not in source are deleted."*

That last part is what sets it apart from **Copy**, which only ever adds and updates. Point a one-way sync at a folder that holds other things and they'll be removed. Try it first with [Dry run](https://storagestudio.us/wiki/glossary-dry-run) to see exactly what would change.

If both places change and you want each to pick up the other's changes, that's [two-way sync](https://storagestudio.us/wiki/glossary-two-way-sync).

See also: [Copy, Move, Sync or Two-way sync](https://storagestudio.us/wiki/copy-move-sync-or-two-way-sync) · [Trying a transfer first with Dry run](https://storagestudio.us/wiki/dry-run)

## What links here

- [Copy, Move, Sync or Two-way sync](https://storagestudio.us/wiki/copy-move-sync-or-two-way-sync)
- [Dry run](https://storagestudio.us/wiki/glossary-dry-run)
- [Two-way sync](https://storagestudio.us/wiki/glossary-two-way-sync)