Are Your WordPress Themes Flexible or Fast?


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If you’ve developed WordPress themes for mass distribution, you might have come across the problem of finding the perfect balance between building performant themes and building feature-rich, media-heavy products for your customers.

Let’s look closer into what the tension might be all about and how you can find ways to compromise between creating fast-loading themes and giving users the flexibility and easy customization options they love and expect.

Are Flexibility and Performance at Odds When Coding WordPress Themes?

I will start by saying that my discussion is not going to be about performance in relation to an entire WordPress website, which might include a number of different factors like finding a great hosting provider, implementing caching mechanisms, leveraging both back-end and front-end techniques, etc.

Also, the topic is not about the performance of WordPress themes you code from scratch either for your own use or for a specific client. In these particular cases you tailor your themes to the specific needs of yourself or your individual client, which should make performance optimizations easy to accommodate.

Rather, my focus will be on WordPress themes you code for the general public, to be distributed on or an online marketplace. The scenario is one where you, as the theme developer, have no control over how your theme is going to be used and customized.

But why could coding for performance clash with coding themes for the public?

On the whole, performance requires you to:

  • stick to simple designs
  • include a limited number of features into your themes (more features are likely to require more processing power and resources, all of which impacts on theme performance)
  • add the minimum number of page templates for a theme to function (fewer templates require fewer resources, which is good for performance)
  • perform as few database queries as possible (querying the database takes time)
  • limit the number and size of images and other media, which are notoriously heavy files
  • minimize the number of HTTP requests (each round trip to the server and back takes some time with obvious negative consequences on performance).

On the other hand, a considerable number of your theme’s users are likely more entrepreneurial than tech minded. Therefore, what they might be looking for is a product they can turn into pretty much anything without so much as one line of code, with lots of functionality out of the box, breathtaking photo and video assets, super delightful parallax and other animation effects, and such like.

To give theme users all the flexibility they would like could come with some performance costs. But let’s go into a few specific points that illustrate how this can happen and how you can find some middle ground for a successful outcome.

Themes are for appearance, plugins for functionality

Although a number of reputable WordPress experts have been throwing some well-argued criticisms against the so-called kitchen sink themes — that is, those multipurpose themes that can become anything to anybody by offering any functionality under the sun — the demand for them is still going strong.

Themes that give users the ability to easily add social media buttons, SEO features, contact forms, price tables, etc., while attracting a lot of attention from buyers, don’t come without some serious drawbacks.

In particular, this kind of WordPress theme comes tightly coupled with plugins specifically built for it, or even integrated directly into the theme. This practice is widely frowned upon for the following reasons:

  • Some of the plugins that come bundled with a theme can have vulnerabilities that put theme users at risk. If the theme doesn’t come with specific plugins installed it’s less open to such risks
  • A super important drawback of tight integration between themes and plugins is what Ren Ventura identifies as theme lock. Here’s his explanation of this problem:

    Theme lock occurs when a WordPress user cannot change his or her theme without gutting most of the site’s functionality. Once the theme is deactivated, it deactivates things like shortcodes and custom post types that were registered by the theme. Without these features that the user has heavily incorporated into the site, things fall apart.

    As a consequence, when you change theme, a lot of the stuff you thought it was part of your website content disappears with the old theme. For instance, if your theme offered the ability to add testimonials to your website, once you change theme all the content related to your testimonials will be gone. Not nice.

  • And of course, bloat and hence performace costs. Let’s say you don’t need a testimonials section on your website. Yet, all the code that makes that functionality work in the theme is still there: it takes up space on your server, which ultimately costs money.

A great maxim the Theme Review Team (i.e., the volunteers who review themes submitted on the themes repo) rightly enforces is: keep functionality separate from appearance. Plugins deal with functionality, themes with appearance. Getting rid of all the complication will improve theme performance and at the same time make it easier for users to install and configure WordPress themes.

Your users don’t need tons of theme options (but they might not know this)

Until not long ago, WordPress themes included rather complicated theme option pages to enable users to make all sorts of modifications with a button click.

These days, thanks to a momentous decision taken by the Theme Review Team on in 2015, most themes offer theme options using the WordPress Customizer, which makes possible live previewing the changes as they’re being made by users.

Unfortunately, the kitchen sink mentality that ruled the old theme option pages has started to migrate to the Customizer, which you can now see as also starting to get filled up with all sorts of settings.

Although non technical customers love theme options to make changes to their themes, sometimes too many options available bring more problems than they seemingly solve:

  • Too many options can paralyze users who are not too familiar with core principles of website design.
  • It can take more time than expected to set up and configure a theme.
  • It’s easy to make mistakes like choosing the wrong colors, making text unreadable, etc.
  • Users might add too many fonts to their themes, thereby spoiling the design and slowing down the website.
  • More options means adding more functionality to the theme, thereby impacting on its performance.

Although your customers might not accept this at first, you are the theme designer, therefore you should be the one who is best placed to make the important design decisions for your theme.

A well-calibrated number of theme options should be sufficient to let your customers make some targeted and carefully predefined (by you) modifications to personalize the theme and make it their own.

Implement smart graphics optimization techniques

Images are likely to put the heaviest weight on theme performance compared to template files, scripts and styles. Just run any theme through Pingdom’s Speed Test tool to verify this.

However, a generous use of full-screen, bold images is hardly surprising. Images add huge aesthetic value to themes and customers are drawn to a theme largely on the basis of its visual impact.

Although it’s hard to resist the power of great graphics, the guidelines below can help you code faster themes without necessarily sacrificing aesthetics (too much):

  • Using as few images as possible is always a good guiding principle.
  • Take advantage of CSS blend modes, filters, and semi-transparent overlays on low-resolution images to mask pixelation and enhance their visual appearance. You can also try to experiment with CSS blend modes and filters on HTML elements and text rather than images to create stunning visual effects wherever possible.
  • Make sure the images are of the appropriate format and optimized for web.
  • Where appropriate, use CSS sprites to combine your images into a larger image and therefore reduce HTTP requests.
  • Try implementing lazy loading for images. Doing so will achieve faster page load, and if users don’t scroll to the location of the <img> tag, the image won’t need to be downloaded at all. To lazy load images in WordPress you can choose from a number of good plugins, such as Lazy Load, a3 Lazy Load and Rocket Lazy Load.

Make customer support and education your pillars of strength

Instead of feeding your customers lots of confusing and time-consuming theme options, try offering full support and education on how to use your themes, image optimization, WordPress 101, etc.

You can do so using:

  • blog posts
  • downloadable guides
  • video tutorials
  • FAQs on your website
  • a ticket system for more specific issues that might arise while using your themes.

Sharing the basic know-how about your products and the platform you build for is a great way of making your themes easy to use for your customers and contributes to generate a high level of trust, which is at the core of a healthy and successful business.

Sometimes Flexibility Wins over Performance

There may be a limited number of cases when you don’t think compromising some flexibility for the sake of a small performance gain is a good idea.

A couple of examples come to mind.

When writing DRY code could make your customers unhappy

The first example comes from Tom McFarlin, a well-known WordPress theme developer and author.

In his blog he explains why he decided to include a long list of WordPress template files, thereby going against the DRY coding principle (and also impacting negatively on performance to some extent) while developing his theme Meyer.

Meyer was targeted at bloggers and digital publishers without much WordPress technical knowledge. Knowing that lack of coding experience would not have stopped this audience from tinkering with his theme, Tom McFarlin thought of a way to make things easier for them. He provided his customers with a generous number of template files they could easily copy and paste into a WordPress child theme for customization without hacking the original theme.

McFarlin writes:

If the templates are defined in the base theme — rather than, say, a bunch of developer-ish conditionals — users are going to have an easier time basing their templates off of something that already exists …

So if I had to sum this up in some concise way, I’d say that I — like many developers — want to keep my code as DRY as possible, but there’s a tradeoff that comes with doing so in the context of WordPress theme development.

And I don’t think that staying DRY is the best way to go about it if you’re going to be marketing a product to a wide audience.

Know Your Customer — the Blogger.

Static source code is better for performance but don’t use it in your public themes

My second example of when not to compromise flexibility for some performance gain in your WordPress themes is based on performance advice from the Codex.

You’ll find some great performance tips there, but there’s one I wouldn’t recommend you use, at least if you’re going to release your theme to the general public.

It goes like this:

  • Can static values be hardcoded into your themes? This will mean you have to edit code every time you make changes, but for generally static areas, this can be a good trade off.

    • For example, your site charset, site title, and so on.

    • Can you hardcode menus that rarely change? Avoiding functions like wp_list_pages() for example.

Codex — WordPress Optimization/WordPress Performance

Avoiding unnecessary calls to the database and optimizing your SQL queries are excellent practices every theme should follow.

If your theme runs a bit slow, try looking for problematic database queries that take too long to execute. You can use a plugin like Query Monitor in your development environment to help you with this task.

However, hardcoding bits of information like site title, menu items, etc., is out of the question. Even if your users never change that info once it’s set, they need to set it at least once and they rightly expect to do so using WordPress dynamic capabilities.

Furthermore, even if your theme’s users were prepared to dig into the source code, they would have to hack the theme files to add the required data. This is almost never a good idea, not least because all changes would be overwritten on the next theme update.


Coding WordPress themes for the general public may involve catering for diverse and sometimes incompatible needs: those of your customer base, of web performance, hence the needs of visitors of those websites that use your themes, and even your own needs as WordPress theme designer and creator.

In this article I’ve expressed my views on how to address the dilemma WordPress theme developers might face between the demands of flexibility and those of performance.