Skip to main content
Code42 Support

Backing Up To A Friend's Computer

Applies to:
  • CrashPlan for Home


This tutorial explains how to back up to a friend's computer. Backing up to a friend gives you the advantage of off-site protection, and it's free!


  • Accessibility: Your friend's computer needs to be powered on when you want to back up or restore files.
  • Speed: Because backing up and restoring takes place over the Internet, the initial backup and a complete restore could take a while. You can reduce the time required to back up by "seeding" your backup locally.
  • Security: Your friend is not able to see the files you have backed up. Even though the backup data is stored on your friend's computer, it is encrypted and can only be accessed when you sign in with your account information.  Likewise, you are not able to see your friend's files.

Accept A CrashPlan Invite

Your friend has invited you to back up with CrashPlan. It's free to back up to each other using your own computers. Follow the steps in the Accept a CrashPlan Invite tutorial to get started backing up.

Backing Up To A Friend (Not Yet A CrashPlan User)

Step 1: Invite A Friend To Back Up

  1. Open the CrashPlan app.
  2. Go to Friends.
  3. Click Invite.
    This opens your default web browser and takes you to My Account.
  4. In the text box, type your friend's email address.
  5. Click Add.
  6. From Friendly Backup, choose the computer where you'd like your friend to back up.
  7. Click Confirm and Send Invitation to send an email to your friend.

Step 2: What Happens After Sending The Invitation

Your friend receives an email message that explains what CrashPlan is and how to back up to each other. The message also includes a backup code so your friend can back up to the computer you chose to offer in step 6.

You can limit the amount of disk space that friends are allowed to use for backup on a friend-by-friend basis.

For full details and instructions for your friend, see our Accept a CrashPlan Invite tutorial.

Step 3: Back Up To Your Friend

After your friend has accepted your invitation and registered using the email address you provided, you friend's computer will appear in the list of backup destinations.

  1. Launch the CrashPlan app by clicking the CrashPlan  CrashPlan Icon  icon on your desktop (Windows) or in the task bar (Mac).
  2. (Optional) If you want to change the files to include in the backup, go to Backup > Files > Change... and select the files you want to back up.
  3. Select the friend to whom you want to back up, then Start Backup.

On the Backup tab, you can check on the status of your backup, stop a backup in progress, or resume a paused backup.

Your friend can also go directly to the CrashPlan app or be invited through My Account.

Backing Up To Existing CrashPlan Users

If you want to back up to someone who is already using CrashPlan, ask your friend to tell you the Backup Code that appears on the Friends page, then follow these steps.

Enter Backup Code

  1. Open the CrashPlan app and go to Destinations > Friends
  2. In the Is Your Friend Already Running CrashPlan section, enter your friend's Backup Code.
    Enter Friend Backup Code
  3. Click Start Backup.


Don't want to use friends as a backup destination? Hundreds of thousands of CrashPlan users back up to CrashPlan Central, our secure cloud storage system. When you’re backed up to CrashPlan Central, your backups are offsite, away from any mishaps that could befall your computer. Online backup to CrashPlan Central is included for subscribers of CrashPlan for Home. Learn more about CrashPlan subscription options.


What happens if my friend's computer is offline?

When your friend's computer is offline, the connection between your computers is disconnected. Your computers can be disconnected at any time, and for any length of time—CrashPlan won't delete the files. When both computers are online, your backup will reconnect, and CrashPlan resumes backup from where it left off.

How is my backup archive stored?

Your backup is stored in a folder labeled with the 18-digit computer ID that corresponds to the computer being backed up. The folder contains all of the elements of your backup in an encrypted archive format

What happens if my drive becomes full?

If a drive becomes too full for CrashPlan to continue backing up to it, the CrashPlan app reports Out of space at destination. To continue backing up, you can either move the backup archive to a larger drive, or reduce the size of the archive. Review our troubleshooting article for full details.