Tachyons CSS Framework / Library Review

2019 February 2

I’ve tried to learn many CSS frameworks (Bootstrap, Foundation, and Bulmar) over the years. They never really clicked and styling felt just as painful as ever. But this has changed since I learned about Tachyons. First introduced by Martin Klepsch (thanks Martin!), I learned and started to use Tachyons since late 2018 for the Cljdoc.org project [1]. This is the only CSS framework / library that fit my brain and my workflow. If you are struggling with learning any CSS framework, I hope I could shed some lights by introducing you Tachyons.


Instead of a CSS framework, I consider Tachyons a CSS library. Here’s the marketing pitch from Tachyons’ Github page:

Functional css for humans. Quickly build and design new UI without writing css.

So what’s functional css? Here I quote the explaination from the article In defense of Functional CSS by Mike Crittenden:

Functional CSS basically means that you have a ton of tiny, single purpose classes that are named based on their visual function.

Here’s the definition from John Polacek‘s Let’s Define Exactly What Atomic CSS is:

Atomic CSS is the approach to CSS architecture that favors small, single-purpose classes with names based on visual function.

There seems to be a theme around “small,” “single-purpose,” and “visual” here. But why are small and single-purpose important for CSS classes? It’s because it makes them highly composable. And the visual aspect makes the composable classes very readable and maintainable.

In the rest of the post, I’ll explain why composibility and maintainability make Tachyons a great fit for my brain and then why it fits my workflow. You can also find Tachyons’ creator, Adam Morse, talk about his creation if you’d like to learn his point of view[2].

Composability matters

Coming into CSS with functional programming background, it really troubles me that all the CSS classes are effectively global-mutable-stateful objects. Without a good methodology adopted by the developer, like BEM, all CSS classes have side-effect on the whole document. (See Case 1.) This makes containing and localizing CSS classes a plausible to solve the problem. However, this also elimiates the reusability of the classes. (See Case 2.)

  Case 1
  Globally, any tag with class "link" will have the same style.
  What if some of the link elements want to have a different color, red?
.link {
  color: black;
  text-decoration: none;

  Case 2
  To contain the style within the context, one might create
  many duplicate modifier classes like below:
.resulttable--link-hide {
    display: none;
.header--item-hide {
  display: none;
.article--timestamp-unimportant {
  display: none;

Tachyons (and other functional css libraries) addresses the composibility problems by introducing small, single-purpose classes. Consider the examples above with the functional CSS aproach:

  Functional CSS aproach for Case 1
  Now a black link is just a composition of .black and .text-decoration-none;
  a red link is just .red and .text-decoration-none.
.black {
  color: black;
.red {
  color: red;
.text-decoration-none {
  text-decoration: none;

  Functional CSS aproach for Case 2
  Only one universal utility class for all the modifiers.
.display-none {
  display: none;

“This almost feels like writing inline-css!” and I kind of agree with you. It seems like an common knowledge that inline-css is consider bad (see StackOverflow.) But this seems to be the only obvious way for me to comprehend CSS. I don’t really understand how to effectively take advantage of the cascading aspect of CSS, and functional CSS frees me from worrying about it anymore. With functional CSS like Tachyons, the classes are very composable and give me very little surprises. That is a powerful thing. I’m able to focus more on the design and less about CSS.

Readability leads to maintainability

In the above examples is really not that far away from the actual Tachyons usage. The only difference is the nomenclature (or naming schemes.) In Tachyons, the class names are concise. For example, in the Case 2 above, .display-none is just .dn. Padding starts with p; margin with m. a v h t r b l stands for all, vertical, horizontal, top, right, bottom, left separately. Numbers indicate size. Thus, when I look at a div:

<div class="pa3 mb2">

I can tell immediately without looking at the CSS code (nor do I need to consult the documentation) that this div is: “padding all with 3, margin at the bottom with 2.” (This almost feels like the vim keybindings!) This is such a breeze for me because when I look at the HTML code, the styles are just right there with it, and very readable. I like the conciseness of Tachyons’ class names and its consistency. It takes a bit of practice to get familiar with them, but the pay-off is that - comprehending the styles has become so easy!

Take the above div for example. When I look at the rendered result on the browser and I want equal margin on the top and the bottom, I can simply just add .mt2 (because of the composability so this won’t conflict with my .mb2 nor .pa3), or I can change to .mv2 like:

<div class="pa3 mv2">


I used to think the styling development workflow is:

(Feedback)   (Comprehend structure)                                (Comprehend style)                 (Change)
  See UI -> Find element in the HTML -> Figure out the CSS classes in HTML -> Read style in CSS -> Modify CSS
     ^                                                                                                  |

Now, with Tachyons, the workflow is:

(Feedback)  (Comprehend structure)      (Comprehend style)      (Change)
  See UI -> Find element in the HTML -> Read style on HTML -> Modify HTML
     ^                                                             |

In the high-level, there’s no difference between the two workflow. However, the difference is in the “comprehend style” step. There used to be a gap / disconnection between the CSS class name and the implementation. With Tachyons, you sort of have the entire CSS library memorized because they have very predictable behaviors and names. The result is faster development iterations.

Lastly, I feel this workflow matches very well with the mindset of REPL-driven development in Clojure. The tight feedback loop enables developer to try things as fast as s/he thinks.


  • If you ever struggled with CSS, Tachyons is a great tool for you;
  • If not, learning Tachyons may give you a fresh point of view.


  • [1] Cljdoc is a website building & hosting documentation for Clojure/Script libraries.
  • [2] Adam Morse: Tachyons CSS Toolkit – Devshop London June 2016 Adam Morse: Tachyons CSS Toolkit -- Devshop London June 2016