10 Step Guide to Changing Your WordPress Theme

July 13, 2016 / WordPress

10 Step Guide to Changing Your WordPress Theme

Changing your WordPress theme is, on the surface, a very easy process: find a theme, install it and click activate. Done. Well, not quite. In reality, there’s a lot more that needs to be done before, during and after installing a new theme and in this article we’re hopefully going to stop you from making lots of unnecessary mistakes by showing you our 10 step guide to changing your WordPress theme.

Avoid crash and burn by backing up

When you activate a new theme, some things are permanently changed. Even if you remove it and reactivate your old theme, not everything is guaranteed to work as it did. In addition, you might find that your new theme has compatibility issues with your plugins and causes internal errors that break your entire site. If this happens, you need to be able to restore your website back to its pre-installation, working version. So, before you start the process, backup your entire website, including the database.

Tell your visitors you’re updating

WP maintenance mode

Installing a new theme properly takes time and means your site can be offline for a while. If you have a mailing list, send out an email telling your regular visitors what’s happening and when. This way, they will know not to visit at those times.

At the same time, download and install a maintenance plugin. You can configure this to let visitors know that you’re temporarily offline for scheduled maintenance. This will stop people seeing a half finished website when they visit.

If you have a page-builder, copy and save your content

Many themes, especially from third-party companies like Theme Junkie and Elegant Themes, come with a built-in page builder. These page builders enable users to create page templates and designs that are difficult to achieve with just a WordPress text editor.

One of the problems with page builders is that you input the content directly into their templates rather than into the WordPress text editor. This means, that when you change the theme and the page builder becomes inactive, the content disappears.

Domain Name

The only way to put it back again is to copy the content before you change the theme and paste it back into the WordPress text editor when you have finished. Unfortunately, you will only have the content, not the original layout which the page builder created, so you will need to reformat this too.  If most of your content was built using this method, this could take some time to do.

Check your old theme’s widgets

Some themes come with their own built-in widgets, just like the page-builder mentioned above, these widgets will disappear when you change your theme. If you have used these widgets, make a note of what you have used them for and if you can, copy the content. For example, if you have an advertisement widget, copy the code for the advertisement. Your new theme may have its own version you can copy it back into, or alternatively, you may have to use a text widget instead. There is, however, no guarantee that the functionality you had will be replaced by the new theme.

Keep a record of your script changes

Many WordPress users do low-level modifications to their theme by making changes to the functions.php file or by customising CSS. Some themes allow you to do this with a special editor, some people create a child theme, whilst others modify the actual theme itself. Whatever modifications you have made will disappear when the theme changes.

Quite a lot of these modifications, for example, changing font size, may be irrelevant when you change the theme as the new theme may offer better alternatives. Others, however, might be vital whatever theme you use. If this is a case, make a note of the changes so you can add them back in. Importantly, when you do, don’t edit the original files as these will be written over if you update the theme to a newer version instead, use a child theme or a built-in editor.

Keep an accurate record of colour schemes

accurate record of colour schemesIf you want your website to keep the same colour scheme, you will probably need to customise the CSS of your new theme. Make sure you keep a record of the number codes you use.

These will be six figure combinations of letters and numbers with a hashtag at the beginning e.g. #b3f090.

It’s important that you record these accurately if you want text colours and backgrounds to match perfectly with existing images that have been used for a colour scheme.

Post Installation

In the next section, we discuss what you need to do after you have installed the new theme. If you need help doing this read our article on How to install a WordPress theme. If you’re still looking for a new theme, we have a handy guide to helping  you choose the right theme, which you may find useful, too.

Reconfigure your settings

One of the first things you may notice after you have installed a new theme is that your homepage disappears. This is because your new theme may have reconfigured WordPress back to default settings. As a result, your homepage may now be set to posts rather than a static page and you will need to change it back again. This maybe only one of several issues that need fixing. Others include:

  • Missing sidebars you may need to configure page layout settings.
  • Missing custom sidebars you will need to retell the sidebar plugin which sidebar to replace.
  • Wrong menu showing you will need to put the right one back in the menu options.
  • Missing header images your new theme will need to know what image to use. (Note: your existing image may be the wrong size for your new theme.)

Configure your new theme

Your new theme will have its own defaults and you may want to change these to meet your needs. You will need to go to your theme settings or customize theme options to change these.

Some themes have very few options available which can be restrictive; at the other end of the scale, there are themes with so many options that setting up can become quite a laborious process. As a rule, always have your theme’s documentation handy to save you making mistakes.

Image problems

One noticeable problem when you change theme is that the images which looked fine on your old theme now look blurry. The reason for this is that different themes have different default image sizes.

When you upload an image to WordPress, it keeps the original image (what it calls full size) but also creates several different versions  thumbnail, medium and large. If the large on your old theme was 800p x 500p and the large on your new is 1000p x 650px, the original images will be stretched to fit the new dimensions and this will make them look grainy or blurred.

To fix this you need to install a plugin called Regenerate Thumbnails. This plugin will use your original full-size image to make a new set of thumbnail, medium and large versions that match the image size of your new theme. Depending on how many images you have, it can take quite a while to process.

Test your new theme

Once you are happy with the configuration of your new theme you need to ensure that all the functionality you had previously, still works. This includes: checking responsiveness on different devices; ensuring payments gateways and user logins work; make sure all pages, posts, product pages and other content types are displaying as expected; check essential info is still accessible (T&Cs, privacy policy, contact page, etc.); make sure widgets are displaying properly and that all plugins are compatible; finally, check that all navigation methods work (menus, breadcrumbs, internal and external links, image links, etc.).

In addition, it is advisable to check that your new site loads quickly to do this visit Google’s PageSpeed Insights and test a range of your pages. If the new theme loads significantly slower, this may affect your site’s ranking. To rectify, follow the suggestions given by PageSpeed Insights after your tests have been completed.


Updating your WordPress theme can be very beneficial, not just in terms of appearance but also in terms of speed and additional functionality. However, from reading this article, you will be aware that is not as straightforward as it first seems and that to avoid major issues you need a methodical approach.

If you are using a WordPress website and are looking for a WordPress dedicated web host, visit our WordPress Hosting page.


  • Arjun Shinde

    I'm an experienced digital marketer with expertise in planning, SEO, SEM, and social media. I'm good at creating engaging content and optimising campaigns for a strong online presence.


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