What is Incremental Backup and How Does it Work?

Incremental Backup BackupVault

Incremental backup is an important part of any online backup service. Typically, tape/disk backup uses either a full or differential method to back up your data. Let’s briefly explain each of these:

  • Full backup – as its name suggests, a full backup creates a copy of all your files and folders
  • Differential backup – this backs up only the files that have changed since the last full backup

Incremental backup, then, only sends the changed parts of a file to the storage servers, and this is what makes online backups so efficient, as it reduces the backup time considerably.

Another benefit to incremental backup is that it enables users to have multiple versions of all files. As standard, our online backup service allows you to access multiple versions of a file going back up to 30 days. We can also increase the retention to months or even years.

How does incremental backup work?

Incremental backup works by only backing up what has changed since the last backup, either full or incremental. The best way to explain this is by using a working week as an example…

The backup software performs a full backup of the selected files and folders. The backup is then compressed and encrypted and sent to the BackupVault servers. This may take some time to transfer, depending on the size of files selected.

The backup software scans the backup selection and sends only new files and the changes of existing files. You would now have a second version of the changed files.

The backup software scans the backup selection and sends only the changed files from Tuesday. You would now have a second and third version of the changed files. New files created are also backed up.

This is repeated each day and after 30 days you would have 30 different versions of changed files. You will also have the ability to restore any one of these files at any one of these backup dates.

Benefits of incremental backup

  • Faster backups – incremental backup only backs up changed files, it’s quicker than other types of backup
  • More efficient storage – data saved in smaller increments means it takes up less space
  • Different versions of files – you can access previous versions of files that have been incrementally backed up


  • Restoring data can take a little longer – the time saved in backing up the data gets added to the time needed to restore it. The last full backup will need to be restored and then each following incremental backup will also need to be restored to give you a complete data set


Incremental backup works by only copying the data that has changed since the last backup, and is especially suited to situations where backing up a large amount of data every time would be time-consuming. However, it’s worth bearing in mind that the time you save backing up incrementally is balanced out by the time it can take to restore the complete data set in the event of a loss.

Backup Vault protects your data with the highest level of encryption, and our cloud backup service is automated and scalable. If you need any assistance in planning and implementing your backup strategy, get in touch with us today.


Editor’s Note: This post was originally published in November 2010 and has been updated for accuracy and comprehensiveness.