Seven simple steps to a snazzy new-look blog: preparing to change template in Blogger

This article is about making a plan to change your Blogger template if your existing blog-template has been customised: it covers how to make a list of the changes that have been made to your template, and using this as the basis of a list of changes to re-apply when you change templates.

Changing your template in Blogger is easy: you just go to the Template tab, choose another template, click Apply to Blog and the changes are applied.

But if you have ever customised your template using the Edit HTML feature, then all the customisations are lost when you change templates. This is fine for some things (eg hiding features you didn't like in a particular template), but it means you lose changes that you may want to keep, eg a favicon, meta-tags, Google Analytics or Webmaster verification, Amazon Product Preview, etc - in short anything that you want to keep, no matter how your template looks.

If you're worried about the consequences of changing templates, you have a basic choice to make:

1 Remember what you did:
Try to remember what you've set up on your blog, and think about which of these things you want to apply in your blog-with-a-new-template.

2 Code comparison:
Compare the layout-template code for your blog with the same code from another blog that has the same template and widgets as your blog, but not the HTML customisations. From this comparison, make a list of what customisations you need to re-apply after you change templates.

The first option is quicker and a lot easier - but you might miss something important. Personally it's not an option I'd like to use for any blog that has "weight".

Unfortunately the second option doesn't give a 100% correct list of customisations, unless you kept a copy of your current template at it was at the time when you first applied it to your blog. This is because Google may have upgraded their copy of the standard version of your template, but not been able to upgrade your customised version. (See Advantages and Disadvantages of Editing Your Blogger Template for more about this). However the list that you can make may be close enough - and I used it myself to make sure I didn't miss any details in migrating the blog you are reading now.

This article is about the second option, and how to use the results of the comparison to make a detailed plan for moving your blog from one template to another.

How do to a code-comparison

Follow these steps to compare the template from your blog with another un-customised version of the template:

1 Make a test-blog which is like your Real-blog, except it doesn't have the layout-template customisations. See Making a test-blog for more details about this: it's NOT as simple as just copying the template over.

IMPORTANT: If you do have a backup copy of your template from immediately after you last applied a new template to, then apply it to your test blog before giving it any widgets. (Doing this will give you the chance of making a 100% correct list.)

2 Working line-by-line, compare the template code in your test and main blogs.

For each difference, work out whether it's due to a customisation that you want to keep when you "migrate" your main blog to a new template, or something that you can leave behind.

To do the comparison:

Get the template code for your test-blog by choosing Template > Backup / Restore > Download Full Template. Save the downloaded file somewhere with a name like testBlog-Template.xml

Get the template code for your main blog the same way Save the downloaded file with a name like realBlog-Template.xml

Use a text-file comparison tool to find the differences between the two files.
Comparing two text files using Excel discusses this in more detail, and links to a tool that makes this process (a little) easier.

Note that there may be some differences which aren't explained by modifications that you made to the template: these will be due to improvements that Google have made to the template file. You need to decide how much time to spend investigating each difference, based on how likely it is that you made it.

3 From the list of differences, write a plan of the existing customisations you want to apply to your new template, and also of any new changes that you want to make at the same time. Put it in order of most-to-least important (eg I usually put "load Google Analytics code" just after "apply template, because the statistics are very important to me).

3.5 (optional) Decide which new template to use, and practise the upgrade:
Use the test-version of your existing blog (the one you made in step 1), and give it the new template. Apply the extra customisations from your list. Possibly even copy in some posts from your main blog into it. Test how well it works, and tweak your list of the changes that need to be made when you migrate your real blog.

4 Back up the current template of your blog.

5 Apply the new template you've selected to your blog.

5.5 (Optional) make another back-up of your template - before you re-apply any of the customisations. This will be the basic version that you compare against if you ever need to do this exercise again, so save it somewhere safe.

6 Make the other changes from your plan.

7 Test your blog to see that all is well.

That sounds easy enough. Seven simple steps to a snazzy new-look blog.