Why do some popular websites have cryptic page sources

daveson217 profile image David Babalola ・1 min read

I recently decided to inspect the page sources of some popular sites to check out the CSS used on the avatars. I noticed two things in particular:

  • The class names used are just cryptic. They just have random letters e.g. s-v7te9w.
  • They use so many divs and other tags to achieve a desired effect (like avatars).

In contrast, Dev.to does not have cryptic class names (e.g crayons-avatar__image), and also does not use many tags to achieve its own avatar(for instance) styling.

These are my questions:

  • Why are the class names so cryptic? Is it because of a framework? Are they dynamically generated?
  • Why are there so many divs(and other tags) just to do one task? Aren't they unnecessary?

Thanks a lot 😁


Editor guide

most complex SPA and even now static web sites and web application generally compile and transpile their typescript, javascript, or now even web assembly. The names can be reversed engineered with what is called a symbol map. these are typically not shared and are auto-generated by the transpiler or compiler. You can also create your own using the tool babylon. This is how we support future future of javascript. These principals also apply to css using libraries and toolkits such as SCSS and LESS. Thank you.


The many divs are a result of abstracting every little detail into their own element or class. Taking Twitter's like button as an example:

<div class="css-1dbjc4n r-18u37iz r-1h0z5md">
    <div aria-label="5 Likes. Like" role="button" data-focusable="true" tabindex="0" class="css-18t94o4 css-1dbjc4n r-1777fci r-11cpok1 r-1ny4l3l r-bztko3 r-lrvibr" data-testid="like">
        <div dir="ltr" class="css-901oao r-1awozwy r-1re7ezh r-6koalj r-1qd0xha r-a023e6 r-16dba41 r-1h0z5md r-ad9z0x r-bcqeeo r-o7ynqc r-clp7b1 r-3s2u2q r-qvutc0">
            <div class="css-1dbjc4n r-xoduu5">
                <div class="css-1dbjc4n r-sdzlij r-1p0dtai r-xoduu5 r-1d2f490 r-xf4iuw r-1ny4l3l r-u8s1d r-zchlnj r-ipm5af r-o7ynqc r-6416eg"></div>
                <svg viewBox="0 0 24 24" class="r-4qtqp9 r-yyyyoo r-1xvli5t r-dnmrzs r-bnwqim r-1plcrui r-lrvibr r-1hdv0qi">
                            d="M12 21.638h-.014C9.403 21.59 1.95 14.856 1.95 8.478c0-3.064 2.525-5.754 5.403-5.754 2.29 0 3.83 1.58 4.646 2.73.814-1.148 2.354-2.73 4.645-2.73 2.88 0 5.404 2.69 5.404 5.755 0 6.376-7.454 13.11-10.037 13.157H12zM7.354 4.225c-2.08 0-3.903 1.988-3.903 4.255 0 5.74 7.034 11.596 8.55 11.658 1.518-.062 8.55-5.917 8.55-11.658 0-2.267-1.823-4.255-3.903-4.255-2.528 0-3.94 2.936-3.952 2.965-.23.562-1.156.562-1.387 0-.014-.03-1.425-2.965-3.954-2.965z"
            <div class="css-1dbjc4n r-xoduu5 r-1udh08x">
                <span class="css-901oao css-16my406 r-1qd0xha r-n6v787 r-1sf4r6n r-1j6idkz r-utggzx r-d3hbe1 r-1wgg2b2 r-axxi2z r-qvutc0"><span class="css-901oao css-16my406 r-1qd0xha r-ad9z0x r-bcqeeo r-qvutc0">5</span></span>

Digesting this is an awful lot of work, but here goes!

<div class="css-1dbjc4n r-18u37iz r-1h0z5md" />

One element in a group of many similar ones (outer role="group" div is missing here). There are multiple different renders of this "component" which is why there are more than one class. In BEM with CSS utilities this would have been something like <li class="like-list__item flex-start flex-direction-row">.

<div class="css-18t94o4 css-1dbjc4n r-1777fci r-11cpok1 r-1ny4l3l r-bztko3 r-lrvibr" />

The second div appears to be dedicated to accessibility and functionality, and re-implements HTML's native <button> element. It is easier to style a div than a button so that is probably the reasoning for the re-implementation. They've had to add custom event handlers to match native button behavior (such as enter and space working like a click).

data-focusable="true" is probably somewhat unnecessary workaround to something, the true functionality of tabbability is achieved with tabindex="0". This also only exists because of not using a button element.

Targetting elements when everything is a div is hard they also use data-testid="like" so that they can find the element in their tests.

Equivalent semantic HTML could be something like:

<button class="transparent-button no-focus-outline no-user-select center-content overflow-visible">
    <span class="sr-only">5 Likes. Like</span>
    <!-- more elements here -->

Of course you'd leave out some of "pointless" styles such as center-content, no-user-select and overflow-visible as these don't have real effect to styles in a native button.

Whether to use aria-label or element with a screen reader accessibility class is a matter of taste.

<div class="css-901oao r-1awozwy r-1re7ezh r-6koalj r-1qd0xha r-a023e6 r-16dba41 r-1h0z5md r-ad9z0x r-bcqeeo r-o7ynqc r-clp7b1 r-3s2u2q r-qvutc0" />

This element appears to be a generic layout component. The first class defines a few resets while all the other classes are single purpose utilities that control things such as font-family, font-size, white-space, transitions, flexbox, and so on.

In a normal HTML approach this element would not exists at all and button would have all the needed classes.

Two <div class="css-1dbjc4n r-xoduu5" /> elements

These are child elements for the generic layout element. Essentially contains a lot of style resets. The first element contains icon, and the second element contains the number of likes.

<div class="css-1dbjc4n r-sdzlij r-1p0dtai r-xoduu5 r-1d2f490 r-xf4iuw r-1ny4l3l r-u8s1d r-zchlnj r-ipm5af r-o7ynqc r-6416eg"></div>

This element creates a circle that is placed behind icon. You can see it transitioning when liking a post. The circle is created by combining many classes.

<svg />

It's the icon!

<span /> elements

These two elements wrap the number. Again contain a lot of style resets and then use of single purpose classes some of which grant duplicate styles that already exist.

How could it be written?

If written more from the point of HTML and CSS things could look like this:

<li class="inline-reset">
    <button class="transparent-button flex flex-center system-font">
        <span aria-hidden="true" class="icon-container circle"><svg ... /></span>
        <span aria-label="5 Likes. Like" class="">5</span>

It is an oversimplification as far as used classes go, but the reduction of HTML elements is notable and the same visual end result can be achieved with just this.

Twitter ends up with what they have for multiple reasons, for example they can have productive devs working on the frontend who have no knowledge of CSS. They can keep total amount of CSS somewhat minimal even if there are classes or styles that are technically unnecessary. The price they pay is the need of re-implementing native browser features and the resulting DOM/HTML is verbose.


😲😲😲. This is really enlightening. Thanks, Vesa.


Thank you for this detailed rundown!

  1. The stupid class names are because of CSS-in-JS. People are afraid of the cascade in CSS, so they use JavaScript to generate ridiculous class names. It goes against the grain of CSS. The cascade is awesome.

  2. Good question. They really should be using simpler and more semantic markup.


Thanks, Kieran. I now get it.


No worries, man. I'm quite vocal about this stuff. I think you might like The Lean Web!

Thanks again Kieran. I surely would love the book(The Lean Web). I'm a fan of keeping things simple 😀

You can read it, and watch the talk, for free!


I would encourage you to take a look at the HTML output from tools like Adobe Dreamwever or other similar WYSIWYG HTML editors. It's quite often horrendous unintelligible code that's functionally useless for anything except being used in the editor that generated it or displayed in a web browser.

As a general rule, when you see that type excessive tag usage, it's a code generator of some sort that's to blame. Sometimes you do need a lot of <div> elements (see for example Bootstrap dialogs, they actually do need all the involved <div>'s to properly handle styling in a uniform manner), but most of the time it's a case of lazy code generation, not actual need.

Styles are often a more complicated case to concretely diagnose though, but most cases seem to be people trying to circumvent some of the behavior of CSS (usually because they don't understand how to actually use it to do what they want in a much more efficient way).


Thanks, Austin. I would check it out.


One added benefit is to make it diffult for the script kiddies to write automation tools to extract data or automate spamming behaviors.




🤔🤔🤔 Thanks, John