Your site feels outdated, or you've just started and the default theme doesn't suit your business. You can install a WordPress theme via View > Themes > Add New Theme, after which you click on Install and Activate Click, and then make adjustments in the Customizer or, if you're using a block-based theme, in the Site Editor. Installation takes two minutes. The decision you make beforehand deserves more time, because you'll be working with that theme for years.
What Makes a Good Theme
A good theme is fast, is actively maintained, fits the way you build your site, and does nothing more than provide a design. A theme determines the entire look of your site, from layout and colors to fonts and the structure of the header and footer. It’s very tempting to choose a theme based solely on the demo, but that demo says little about how the theme will hold up a year from now.
Speed is the most important factor for me. A theme full of sliders, animations, and built-in effects slows down every page, and that’s something you can hardly fix later on. So run the demo through a test like PageSpeed Insights before you make your choice, and read more at Causes of a Slow WordPress Website why the theme plays such an important role in this. Then check the theme page to see when it was last updated and which version of WordPress it was tested with. A theme that hasn't been updated for a year will sooner or later stop working due to a WordPress or PHP update.
Next, choose a theme that suits your editor. If you’re using the block editor, a block-based theme is the obvious choice. If you’re building with Elementor, choose a lightweight theme designed for it, such as Astra or GeneratePress. At Surver, we install WordPress on a new package with Astra and Elementor by default, using the free version of Astra unless you have the Starter Pack with Astra Pro. My final rule is that functionality belongs in plugins, not in your theme. If your contact form or SEO settings are built into the theme, you’ll lose them as soon as you switch themes. You can read more about this distinction in Choosing and Managing Plugins and Themes.
Before you make changes to an existing site
Installing a theme is harmless, but activating it immediately changes the design of your entire site for all visitors. Your text, pages, and posts will remain intact, since they’re stored in the database and not in the theme. What might shift, however, are widgets, menu items, and anything the old theme added itself, such as shortcodes or custom page templates. On a site that’s been up and running for a few years, I almost always come across something that needs to be redone when switching themes.
Therefore, use this first Live example. That button appears when you hover your mouse over an installed theme, and it lets you preview your site in the new theme without visitors noticing. Next, create a backup so you can revert if things don’t turn out as expected. On Surver’s shared hosting plans, we create a daily backup, and you can set up an additional one yourself in Installatron. Instructions on how to restore it can be found in Restoring a WordPress Backup.
My advice for any serious website is to first thoroughly test a theme change in a staging environment. You can do this in Installatron by cloning your installation. There, you can take your time reassigning menus, moving widgets, and reviewing each page, and only once everything is correct should you apply the changes to your live site.
Installing and Activating a Theme
You can install a theme from the official library or as a ZIP file, which is common for paid themes. Here's how it works.
- In the dashboard, go to View > Themes and click at the top on Add a New Theme.
- Search for the theme by name or use the filter by features. If you have a ZIP file, click on Upload Theme, select the file, and click Install Now.
- After installation, click Live example to view your own content in the theme.
- Click on Activate. The new theme is now live.
- Check your homepage, the menu, and the widgets, and under View > Menus If necessary, reassign the menu location.
If you're working in the command line, do the same thing with wp theme install astra --activate. WP-CLI is included in all of Surver's shared hosting plans. If an upload returns an error message about the file size, check to see if you've accidentally uploaded the entire download package instead of the theme file itself. With paid themes, the actual theme is often included as a separate ZIP file within a larger package that contains documentation.
Customize Your Theme
How you customize a theme depends on the type. For a classic theme, you use Appearance > Customizer. There, you can change your logo, colors, fonts, and layout in a sidebar while viewing the site in real time, and you don't publish until you're satisfied. In a block theme, this is called the Site Editor, which can be found under View > Editor. There, you can edit the templates for the header, footer, and pages yourself using blocks, just as you would with a regular page.
Start with the basics—the logo, colors, and fonts—and only then look at the details for each page. This way, you’ll avoid creating isolated exceptions throughout the site that are difficult to maintain later on. Paid themes like Astra Pro often have their own settings panel in addition to the Customizer, with extra options for the header or blog layout. If you’re still figuring things out in the dashboard, the Tour of the WordPress Dashboard.
Any settings you configure through the Customizer or Site Editor will survive a theme update. That’s the safe approach, and for most sites, it’s sufficient. It’s only when you start editing the theme files themselves that things change.
Customizing the code and cleaning it up
If you plan to edit your theme’s code yourself, always use a child theme; otherwise, the next theme update will overwrite all your customizations. A child theme is a subtheme that inherits everything from the parent theme, while your CSS and functions are stored in a separate style.css and functions.php are. Unfortunately, with new clients, I often find customizations that have been lost during an update. You can read how to create one in Creating a Child Theme in WordPress, and where you can safely edit code in Editing WordPress Code.
If your new theme is working as expected, delete the old themes via Theme Details > Delete, except for one standard WordPress theme that you keep as a backup. Even inactive themes are stored as code on your server and may contain vulnerabilities. You should then keep your active theme up to date as a regular part of your maintenance routine, along with the core and plugins, as described in Update WordPress.
If you'd rather have someone else handle the interior design, our team will build or renovate your webmaster service your site using the theme of your choice. Updating the theme, core, and plugins is covered under WordPress maintenance. And if you choose Managed WordPress Hosting, WordPress, Astra, and Elementor will already be set up and ready to go when you start.
Frequently Asked Questions
Will I lose my content if I switch themes?
No. Pages, posts, and images are stored in the database and will be preserved. What may change are the layout, widgets, menu locations, and features that the old theme itself added.
Should I choose a free theme or a paid one?
A well-maintained free theme is sufficient for most websites. A paid theme makes sense if you actually use the extra features and renew the license, because without a license, you often won't receive updates anymore.
Can Surver set up a theme for me?
Yes, Surver uses the webmaster service to set up your theme and build the pages. If you'd like to do it yourself, the Astra theme is already available for you in a new package.