What are they useful for ?
If you optimize your images with reSmush.it Image Optimizer, it will keep your original images as a backup (files named -unsmushed.jpg). If you change the optimization level, your images will be optimized based on your original files (the backup).
Important: If you keep backup files, no backup images will be made available to your visitors. Therefore, your application is already blazing fast for end users.
What is the risk of removing my backups ?
If I delete my backups, I will no longer be able to :
- Restore the original image files: They would have been replaced by optimized images.
- Change the image quality factor to a better value. If you have already optimized your entire library to a quality factor of 80, changing the quality from 80 to 92 will not improve your images. It will try to optimize them based on images with a quality of 80, which is not efficient.
Disabling backups and setting a low quality factor (e.g. 20) is therefore a destructive approach for your library
What is the benefit of removing backup files ?
It reduces the overall size of your websites on your web server, but has no impact on the image size for end users as it only removes the backup files.
So, what should I do ?
Unless you want to reduce the size of your website on your web server (which is not really costly), we advise you to keep backup files so that you can restore your original images if you want to increase the quality factor.
Important reminder
In the event of data loss or destruction of your library, you bear full responsibility. Make sure that you or your hosting provider have working backups of your entire website.