---
title: "Two-way sync"
url: https://storagestudio.us/wiki/glossary-two-way-sync
category: "Glossary"
tags: ["glossary", "data transfers", "sync"]
summary: "Two-way sync keeps two places the same by copying changes in either direction. In Data Transfers it is called Bidirectional sync."
updated: 2026-10-01T05:35:59.000Z
---

# Two-way sync

Two-way sync keeps two places the same by copying changes in either direction. In Data Transfers it is called Bidirectional sync.

**Two-way sync** keeps two places the same by copying changes in **either** direction: add, edit or delete a file on one side, and the same happens on the other. If the same file changes on both sides between runs, that's a *conflict*.

In Data Transfers this is the **Bidirectional sync** operation: *"Keep both sides in sync. Changes on either side propagate to the other. Conflicts logged."*

The very first run for a pair of places needs the **First run for this pair** box ticked, so Storage Studio can record a starting point. Never tick it again on later runs for the same pair — it would overwrite one side with the other.

If you only want changes to flow one way, use [one-way sync](https://storagestudio.us/wiki/glossary-one-way-sync) instead.

See also: [Two-way sync and the First run box](https://storagestudio.us/wiki/two-way-sync-first-run) · [Copy, Move, Sync or Two-way sync](https://storagestudio.us/wiki/copy-move-sync-or-two-way-sync)

## What links here

- [Copy, Move, Sync or Two-way sync](https://storagestudio.us/wiki/copy-move-sync-or-two-way-sync)
- [One-way sync](https://storagestudio.us/wiki/glossary-one-way-sync)
- [Shared Folders: keeping a folder the same on two Macs](https://storagestudio.us/wiki/shared-folders-between-macs)
- [Two-way sync and the First run box](https://storagestudio.us/wiki/two-way-sync-first-run)