---
id: data-transfers.why-is-a-repeat-transfer-faster
url: https://storagestudio.us/faq/data-transfers/why-is-a-repeat-transfer-faster
category: "Data Transfers"
subcategory: "Copy, Move and Sync"
question: "Why does running the same transfer again finish so much faster?"
alt_questions:
  - "second sync only copies changes"
  - "does storage studio re-upload everything each time"
  - "incremental transfer mac"
  - "why did my scheduled sync take seconds"
  - "repeat copy is quick"
short_answer: "Repeat runs only send files that are missing or changed — everything that already matches is skipped. That's also how transfers carry on after a restart."
tags: ["incremental", "speed", "schedules"]
related: ["https://storagestudio.us/faq/data-transfers/does-copy-overwrite-files", "https://storagestudio.us/faq/data-transfers/large-downloads-resume-where-they-left-off", "https://storagestudio.us/faq/data-transfers/what-happens-if-i-quit-during-a-transfer"]
applies_to: "all"
last_reviewed: 2026-10-01
---

# Why does running the same transfer again finish so much faster?

Because only what's missing or changed is sent. Copy and the sync operations compare the two sides and skip files that already match, so a repeat run of a large folder where little has changed mostly just checks and finishes.

The same rule is what lets a transfer pick up after a restart: when Storage Studio relaunches, a transfer that was running goes back into the queue and carries on, sending only what isn't there yet.

One exception: a single file that was interrupted part-way is sent again from the start, unless it's a large download coming to your Mac in pieces, which resumes where it stopped.

Related: [Large downloads that resume](https://storagestudio.us/faq/data-transfers/large-downloads-resume-where-they-left-off)