I’m Theo Marsh, and I built this site because I couldn’t find the manual I actually needed when I was learning HTML.
How this started
I came to web development sideways. I wasn’t a computer science student — I was someone who needed to put a portfolio online and kept breaking things. I spent hours reading documentation that assumed I already knew the terms it was using, tutorials that glossed over the one step I was stuck on, and forum answers that said “just use a framework” without explaining why.
Eventually it clicked, through a lot of trial and error and a lot of “wait, that’s what that attribute does.” When it did, the first thing I wanted to do was write it down — clearly, in the order it actually makes sense to learn it, without the jargon wall.
That’s what htmlblog.net is.
What I write about
The core of this site is HTML and CSS: what elements mean, how the browser renders them, how structure connects to styling, how to build things that work on a phone as well as a desktop. I write for people at the keyboard — the guides include real code you can copy, modify, and run immediately.
Beyond the fundamentals, I cover the practical web: how to open and work with HTML files, how mobile optimisation actually works rather than just “make it responsive,” how to use widgets and embed tools on a site you don’t fully control, and honest takes on the software builders actually use.
I also keep a set of free browser-based tools — an HTML formatter, colour picker, gradient builder, Base64 encoder, regex tester, JSON validator, and more. They run entirely in your browser, so nothing you paste into them leaves your device.
What I’m not trying to do
I’m not trying to cover everything. There are larger sites that index every CSS property and every JavaScript API method. That’s not what this is.
What I try to do is explain things in the order they become useful, connect concepts that documentation treats as separate, and answer the question you actually typed into the search box — not a slightly different question that’s easier to answer.
A few things I’ve learned along the way
- HTML is not hard. What makes it hard is learning it from documentation written for people who already know it.
- Most “beginner” CSS tutorials skip the mental model — the box model, how flow works, why floats behave the way they do — and go straight to property lists. The mental model is the part that makes everything else make sense.
- The best way to learn a new element or attribute is to use it in a real page, break it, and fix it. Reading about it without building is slow and mostly doesn’t stick.
Where to start
If you’re new to HTML, the HTML basics guide is written to be read in order — it covers what HTML is, what elements and attributes actually do, and how a file becomes a page in a browser. The mobile optimisation guide is a good follow-on once you have the fundamentals.
If you already know your way around and you’re looking for a specific tool or answer, the search box at the top of the page is the fastest route. Or browse the tools section — most of the tools have a short explanation of what the underlying technology is and why you’d want to use it.
Get in touch
If something on the site is wrong, out of date, or could be explained more clearly, I want to know. Corrections are welcome — the goal is accuracy, not being right. You can reach me via the contact page or at [email protected].