So be prepared, and if you haven’t yet backed up your blog, then do it now.
Below are 5 ways to backup you Blogger blog:
1. Using blog feeds
First of all you need to ensure the feed contains complete post contents (including images). Go to Dashboard > Settings > Other > Site Feed, and select FULL in the "Allow Blog Feed" dropdown menu.
Go to this URL and save page as "Webpage, Complete" in your PC:
A posts feed retrieves only up to 500 posts and a comments feed up to 200 comments. If your blog has more posts or comments, you need to get more than one feed. Add a start-index query in the URL to specify the starting point of each subsequent feeds, like this:
The same applies to comments feed. If you redirect your blog feed, then append &redirect=false at the end of the URL.
2. Using export featurePosts and comments Go to Dashboard > Settings > Other > Blog Tools and click "Export Blog". The blog posts and comments (in XML file) will be downloaded to your PC.Dashboard > Settings > Other > Blog Tools, then click "Import Blog".)
3. Using Email featureUsing this method lets Blogger send you an email every time a post or comment is published on your blog.
Go to Dashboard > Settings > Basics > Mobile and Email > Email Posts To and enter your email address in the textbox.
Go to Dashboard > Settings > Mobile and Email > Comment Notification Email and enter your email address in the textbox .
4. Using Google Takeout
First go to https://www.google.com/takeout/#custom and Login to your Google or Gmail Account. After logging in to your account, it will take you to a new page here you will see a list of services that you have used through your Google account.
5. Using HttrackHTTrack downloads all files into your PC and creates a mirror copy of your blog offline. You can browse the blog as if you were online, posts, comments and all. HTTrack is available for Windows and Linux. Download it here. Once downloaded use this this instructions to install it in your PC. Enjoy!