An honest comparison from an agency that builds both. Pricing, performance, SEO, maintenance, and how to figure out which makes sense for your business.
WordPress powers about 43% of all websites in the world. Custom-built sites power most of the websites that win awards and rank top of Google. Both have strengths. Both have weaknesses. Neither is the right answer for every business.
This is an honest comparison from an agency that builds both, written for UK business owners trying to make a sensible decision about their website.
Choose WordPress if: You need to publish content frequently, want a large team to be able to edit pages, and your website's main job is communication rather than conversion.
Choose custom-built if: Performance, conversion, and a unique brand experience matter more than DIY editing. You want maximum speed, security, and control.
Now the detail.
WordPress is an open-source content management system (CMS). You install it on a server, choose a theme, add plugins for extra functionality, and manage your site through an admin dashboard. It powers everything from personal blogs to enterprise sites like TechCrunch.
Pros: Easy for non-technical people to add content. Massive plugin ecosystem (over 60,000 plugins). Most agencies and freelancers know it. Good for blog-heavy or content-heavy sites. Loads of pre-built themes available.
Cons: Performance often suffers because of plugin bloat and heavy themes. Security risks from outdated plugins. Pages tend to look like other WordPress pages. SEO depends heavily on configuration. Maintenance is ongoing — plugins, themes, and core all need regular updates.
Typical cost: £1,500-£5,000 to build, £200-£800/year for hosting, themes, and maintenance.
A custom-built website is coded from scratch using HTML, CSS, JavaScript, and (depending on the project) frameworks like Next.js, Astro, or Eleventy. Every design element, every interaction, every line of code is purpose-built for your business.
Pros: Maximum performance — usually scores 95-100 on Google PageSpeed Insights. Total design freedom — no template constraints. Stronger SEO foundation. Better security (no plugins to exploit). Lower long-term costs (less maintenance overhead). Genuinely unique brand experience.
Cons: Higher upfront cost. Non-technical team members can't always edit content directly without a CMS layer. Adding new features requires development work. Fewer freelancers can pick it up if you change agencies.
Typical cost: £3,000-£10,000 to build, £100-£400/year for hosting and maintenance.
Performance is where these two diverge most. WordPress sites with several plugins typically score 30-60 on mobile PageSpeed. Custom sites typically score 90-100.
Why does this matter? Because Google ranks faster sites higher. Because slower sites lose visitors before they convert. Because Core Web Vitals are now an explicit ranking factor. A site that takes 4 seconds to load loses approximately 40% of mobile visitors before they see anything.
You can make WordPress fast — but it takes work, money, and constant maintenance. Custom sites are fast by default.
Both can rank well. The difference is how much work it takes to get there.
WordPress: Strong SEO ecosystem (Yoast, Rank Math, etc.) makes basic optimisation easy. Heavy themes and plugin bloat can drag down performance metrics that affect ranking. Schema markup is plugin-dependent, which means it's only as good as the plugin you pick.
Custom-built: Faster page loads, cleaner code, and proper structured data are easy to implement when you control everything. No plugin compatibility issues. SEO is built in from day one rather than bolted on.
Verdict: Custom wins on technical SEO, WordPress wins on ease-of-management for non-technical users.
Upfront: WordPress is usually cheaper to build (£1,500-£5,000) than custom (£3,000-£10,000). The gap is narrower than people think because a properly-built WordPress site with custom design and good performance optimisation isn't actually much cheaper than a custom build.
Ongoing: WordPress costs more over time. You'll pay for premium themes (£50-£200/year), premium plugins (£100-£500/year), better hosting (£100-£500/year), and ongoing maintenance to keep everything updated and secure (£30-£200/month). Custom sites have minimal ongoing costs — usually just hosting and occasional updates.
Over 3 years, a custom site often ends up costing about the same or less than a WordPress site, while performing better.
WordPress: Constant maintenance. WordPress core, themes, and plugins all need regular updates. Plugins occasionally break each other. Security vulnerabilities are common — over 90% of hacked CMS sites in 2024 were WordPress. You need to back up regularly, update carefully, and test after every change.
Custom-built: Minimal maintenance. No plugins to update. No themes to break. The site sits there and works. When you do need changes, they require development work, but you're not firefighting on a weekly basis.
WordPress: Easy to add new features through plugins (good). Plugins can become abandoned, incompatible, or insecure (bad). Locked into the WordPress ecosystem — migrating off is painful.
Custom-built: New features require custom development, which costs more upfront. But you own everything, you're not dependent on a third-party plugin maintainer, and you can extend the site indefinitely without compatibility headaches.
WordPress sites are the #1 target for automated hacking attacks. The reason is simple: WordPress runs 43% of the web, so if you find a vulnerability in a popular plugin, you can exploit thousands of sites at once.
Custom-built sites have a much smaller attack surface. There are no plugins, no admin login pages bots can target, and the codebase is unique to your business. Most of the common WordPress attack vectors simply don't exist.
WordPress can absolutely be secured — but it requires active maintenance. Custom sites are secure by default.
Want to see the difference yourself? Pick three WordPress sites and three custom-built sites in the same industry. Run them through Google PageSpeed Insights on mobile. The custom sites will almost always score significantly higher. Faster sites rank higher and convert better. The numbers don't lie.
You don't always have to pick one or the other. Some hybrid options:
Headless WordPress: WordPress for content management, custom front-end for the public site. Best of both worlds in theory. More expensive in practice.
Custom site with a CMS: Custom-built site with a lightweight CMS (Sanity, Contentful, Storyblok) for content editing. Fast performance, easy editing, but more technical setup.
Astro or Next.js: Modern static site generators that give you custom-build performance with developer-friendly content editing. Increasingly popular for marketing sites.
The right answer isn't WordPress or custom — it's whichever option matches how your business actually works. If your website is a conversion tool, build it for conversion. If it's a publication, build it for publishing. Pick the tool for the job.
Not sure which is right for your business? Book a free 30-minute call and we'll talk through your goals, budget, and team to recommend the best approach.