Search “pillars of SEO” and you’ll find the same four almost everywhere: technical, on-page, off-page, and content.
SEOsides uses a slightly different four: technical, on-page, UX, and content. That swap is deliberate, and it says a lot about how I think SEO works in practice. More on that below.
Why Think in Pillars at All?
Because SEO problems rarely announce which category they belong to. Traffic drops and you have to figure out whether it’s a crawling issue, a content issue, or something else entirely.
Pillars give you a structure for diagnosing problems and planning work. Each one answers a different question about your site.
Pillar 1: Technical SEO
The question it answers: Can search engines access and process this site?
Crawling, indexing, rendering, site architecture, and performance. Technical SEO is the foundation. When it fails, the other three pillars don’t get a chance to matter. I break it down fully in what technical SEO is and what it isn’t.
Pillar 2: On-Page SEO
The question it answers: Can search engines understand what this page is about?
Title tags, headings, URL structure, internal links, image optimization, and structured data on individual pages. (More in what on-page SEO covers and where it stops.) On-page SEO is how each page communicates its purpose, both to search engines and to the person scanning the results. Internal links are a big part of that, which is why I treat internal linking as a ranking lever.
Pillar 3: UX and SEO
The question it answers: Does the visitor have a good experience once they arrive?
Page speed, Core Web Vitals, mobile usability, readable layouts, and pages free of intrusive popups. Google has spent years pushing page experience closer to the center of search, and its guidance on helpful content asks directly whether people leave feeling satisfied. I break down the specifics in where UX and SEO actually overlap.
Pillar 4: Content SEO
The question it answers: Is this page genuinely worth ranking?
Search intent, topical depth, originality, accuracy, and E-E-A-T. (More in what content SEO is and how it differs from writing.) Content is what people actually came for. Everything else exists to deliver it. The way to build it deliberately is covered in building topical authority with content clusters.
So Where Did Off-Page SEO Go?
Let me be clear: links still matter. Google still uses them to discover pages and judge authority, and anyone who tells you otherwise is guessing.
But I leave off-page out of the SEOsides pillars for two reasons.
First, it’s mostly outside your control. You can’t make other sites link to you. You can only build something worth linking to, and that’s the job of the other four pillars. In my experience, sites that nail technical, on-page, UX, and content tend to earn links as a side effect.
Second, it’s where most of the shortcuts live. Link schemes, paid links, and private blog networks are the fastest way to break Google’s spam policies. A framework built around what you control keeps the focus where it belongs.
Meanwhile, user experience has earned its own seat. It used to be treated as a design concern. Today it’s inseparable from how well a page performs in search.
How the Pillars Depend on Each Other
Here’s the part of the metaphor that matters most. A roof resting on four pillars sits only as high as the shortest one.
Picture a genuinely excellent guide, the best on its topic. But the site loads its text with JavaScript that Google struggles to render. The content pillar is tall. The technical pillar is short. The page sits low.
Flip it. A technically flawless site with thin, generic content has the same problem from the other direction.
That’s why SEO audits that only look at one pillar miss so much. The weakest pillar sets your ceiling.
Where to Start
On an existing site, start with technical. If search engines can’t properly crawl and index what you already have, new content won’t fix it.
On a new site, get the technical basics right at launch, then put most of your energy into content. There’s nothing to optimize until there’s something worth finding.
Every article on SEOsides sits under one of these four pillars. If you’re just getting started, read what SEO really is first, and if paid search keeps coming up in your work, see SEO vs SEM.
