OneSync 사용 가이드

What OneSync is

OneSync is an app for moving files and text between iPhones, Android phones and a computer browser. There is no account and no login. You link devices for a short time with a session code or a QR code, and then upload and download inside that session. It is meant for the situations where AirDrop-style features are not available because the devices run different operating systems: sending a photo from an iPhone to an Android tablet, or pasting a sentence copied on a work PC into your phone.

Screens at a glance

These two screens show the start and middle of the flow. From Home you create or join a session, which opens the session screen.

Who it suits

• People who use both iPhone and Android, or families whose devices differ
• Anyone who needs to move a file or two from a shared or borrowed PC without signing in
• People who find cables, email attachments or messaging yourself too clumsy
• Anyone who wants to copy a link or a passage on one device and paste it on another

It is not a good fit for keeping files for months, or for documents that must never be exposed. The security section below explains why.

Basic flow

1. Create a session

On first launch you see a short onboarding guide. On the home screen, tap Create Session. The app generates a 6-character session code, a 2-digit verify code and a QR code that carries them. A countdown shows the time remaining; the default length is 15 minutes. A session allows up to 10 devices by default.

2. Join from another device

There are two ways to join. You can tap Scan QR Code and point the camera at the QR code on the other screen, or tap Join Session and type the session code and verify code by hand. The first time you scan, you must allow camera access; if you refused, re-enable it in the device settings. On a computer you do not need to install anything: open the OneSync web client (onesync-web-cf.setlog.net) in a browser and join the same way.

3. Upload and download files

In the session screen, choose Upload Files and pick items from your photo library or the Files app. They upload and appear in the Shared Files list on every other device in the session. The other person taps Download to save a file and Open to view it. Large files are sent in chunks, and if an upload is interrupted the app offers to resume it.

4. Share text

Tap Share Clipboard and whatever you have copied is sent to every device in the session and kept in the Shared Texts list. This is handy for long URLs, a temporary phrase needed during a sign-in, or an address that is tedious to retype.

5. End the session

When you are done, tap End Session. It would expire on its own, but closing it yourself shortens the time the code stays valid.

Limits and retention

• Session length: 15 minutes by default. The server accepts lengths from 5 minutes to 1 hour, but whether the app screen lets you choose may depend on the version.
• Participants: up to 10 devices by default
• File size: the service ceiling is about 1 GB per file
• Text size: about 900 KB per share
• Retention: files become eligible for cleanup when the session expires. Cleanup runs periodically, so do not assume files vanish the instant a session ends. Do not rely on OneSync as storage; save what you receive right away.

Privacy and security notes

OneSync has no sign-up and no passwords; devices are identified by little more than a nickname. Files are uploaded straight to cloud storage rather than through an application server, and the receiving device downloads them from there. However, the current implementation does not include end-to-end encryption. Anyone who knows the session code and the matching verify code can join the session, and uploaded files sit temporarily in the service cloud storage. For that reason, avoid sending ID scans, contracts or passwords this way. Keep codes away from people you do not know, and close the session as soon as everyone has joined and received what they need. See the privacy policy for the full statement.

Practical tips

• If you are in the same room, scanning the QR code is faster than reading digits aloud and avoids typos.
• Sessions are short, so choose the files before you start the session.
• Send large files on Wi-Fi and keep the app open until the upload finishes.
• For many photos, send a few dozen at a time so a failure costs you less to redo.

Troubleshooting

"Invalid verification code"

Even with the right session code, a wrong 2-digit verify code is rejected. Re-check the digits on the other screen. After several wrong attempts in a short time you may see a too-many-attempts message and be blocked briefly; wait a moment and try again.

"Session is full"

The participant limit was reached. Check whether a device that already left still counts, or create a new session.

The QR code is not recognized

Check camera permission, screen brightness and distance. A QR code that was not made by OneSync produces an invalid QR code message. As a fallback, type the codes manually.

Connection lost

If you see a message asking you to reconnect, check your network and return to the session screen. If the session has already expired, create a new one.

Limits and known issues

• There is no end-to-end encryption. The current implementation does not include E2E encryption. Anyone who knows the session code and verify code can join, and uploaded files sit temporarily in the service cloud storage.
• It is a temporary hand-off channel. A session lasts 15 minutes by default and files become eligible for cleanup after it expires. Cleanup runs periodically, so files are not guaranteed to vanish the instant a session ends, but do not expect them to be kept either.
• There are limits. Up to 10 devices per session, about 1 GB per file and about 900 KB of text per share. The server accepts session lengths from 5 minutes to 1 hour, but whether the app screen lets you choose may depend on the version.
• Both sides need internet. You need not share a Wi-Fi network, but the uploading and downloading devices must both be connected. If the connection drops you see a message, and if an upload is interrupted the app asks whether to resume.
• Camera permission is needed once. If you refused it on first scan, re-allow it in device settings; meanwhile you can type the codes by hand.
• Repeated wrong verify codes cause a short block. Several mistakes in a short time bring up a too-many-attempts message.

How it compares

OneSync is not always the best choice. Depending on the situation another tool is better.

In short it suits moving a file or two once without logging in, and does not suit long-term keeping or sensitive material. For a wider comparison see the guide to moving files.

FAQ