---
id: data-transfers.what-is-bidirectional-sync
url: https://storagestudio.us/faq/data-transfers/what-is-bidirectional-sync
category: "Data Transfers"
subcategory: "Copy, Move and Sync"
question: "What is Bidirectional sync and when should I use it?"
alt_questions:
  - "two-way sync storage studio"
  - "keep two folders in sync both ways"
  - "How does two way sync work?"
  - "bisync mac app"
  - "sync changes in both directions"
  - "What does Bidirectional sync do?"
  - "two way sync between Mac and cloud"
short_answer: "Bidirectional sync carries changes, including deletions, in both directions between two places, recording conflicts in the log. Tick “First run for this pair” on the very first run, then never again."
tags: ["two-way sync", "bidirectional", "sync", "conflicts"]
related: ["https://storagestudio.us/faq/data-transfers/first-run-for-this-pair-option", "https://storagestudio.us/faq/data-transfers/bidirectional-sync-conflicts", "https://storagestudio.us/faq/data-transfers/schedule-a-recurring-transfer"]
applies_to: "all"
last_reviewed: 2026-10-01
---

# What is Bidirectional sync and when should I use it?

**Bidirectional sync** keeps two places matched in both directions: a change made on either side — a new file, an edit, a deletion — is carried across to the other the next time it runs. If the same file was changed on both sides, that conflict is recorded in the transfer's log.

Use it when you genuinely work in both places, for example a project folder on your Mac and the same folder in a cloud account you also edit from another computer. If changes only ever flow one way, **Sync (one-way)** is simpler and safer.

Two things to know:

- The very first run for a pair of folders needs the **First run for this pair** option ticked.
- Pair it with a schedule so it keeps running without you.

Related: [The First run for this pair option](https://storagestudio.us/faq/data-transfers/first-run-for-this-pair-option) · [Schedule a transfer](https://storagestudio.us/faq/data-transfers/schedule-a-recurring-transfer)