If you’re about to make a modification to your Wordpress theme files that you aren’t sure about, it’s a good idea to backup your theme, especially if your theme is custom-made (i.e. you can’t just re-download it if something goes wrong), or if you have many other theme modifications you want to preserve.

Here are two ways to do it:

The Quick Method

You can easily backup a single theme file by going to the Theme Editor under Design, clicking the file, and then copying-and-pasting the contents of the theme file you’re editing into a Notepad document. Read more detailed steps here.

The Complete Method

These steps will help you backup your entire theme:

1. Download an FTP program (such as FileZilla) if you don’t have one already.
2. While you’re waiting for that, go to your WordPress admin, and then click on “Design” (or “Presentation”).
3. Under the “Current Theme” header, note the file path that comes after “All of this theme’s files are located in.”
4. Once your FTP program is downloaded, installed, and ready to go, connect to your website by entering in your FTP hostname, username, and password (these should be different from your WordPress username and password). If you don’t know what they are, ask your web host for help.
5. Once you’ve connected to your website, browse to the folder that contains your WordPress installation (again, ask your web host if you need help finding it), and then browse to the folder you noted in step 3.
6. Tell the FTP program to download the entire theme folder to a location on your computer.
7. Once that’s done, check to make sure the FTP program says the files transferred correctly.