alt.hn

5/6/2026 at 4:43:25 AM

Multi-stroke text effect in CSS

 https://yuanchuan.dev/multi-stroke-text-effect-in-css

by cheeaun

5/6/2026 at 5:19:21 PM

This is made with (and by the author of) <css-doodle>, a web component that lets you put the CSS variant used in this blog inline into your HTML, like so:

    <script src="https://esm.sh/css-doodle/css-doodle.min.js?raw"></script>
    <css-doodle>
      @grid: 15 / 90%;
      border-radius: 50%;
      background: hsl(@t(/20), 70%, 60%);
      scale: sin(@atan2(@dx, @dy) + @ts);
    </css-doodle>
No JS needed except for loading the definition of the <css-doodle> component. Works in plain HTML, Markdown, frameworks, etc.

https://css-doodle.com/

by spankalee

5/6/2026 at 6:26:47 PM

Thanks for the explanation. I’ve moved away from frontend work in 2018, and I really have no idea what CSS can do anymore! So much of the CSS in this page looks cryptic to me.

Kudos to the author for posting something cool and new in the age of standardised styles.

by port11

5/6/2026 at 7:00:10 PM

css-doodle's syntax has a lot of non-standard-CSS stuff in it. All the @ things are extensions.

by spankalee

5/6/2026 at 10:16:06 AM

I wonder why the firefox CSS rendering engine prefers to smooth out. Looks like a dramatically different implementation, but maybe that's just because it's an edge case of rendering

by HughParry

5/6/2026 at 4:36:21 PM

Stroke expansion is a complex topic, with more than one reasonable result (subjective preferences), and a whole lot of corner cases and incorrect answers.

Firefox has chosen to expand based on distance at all points, which is one of the reasonable answers and probably the most general one; a cusp then expands to a curve.

The others have chosen to retain cusps, which can be a reasonable answer and I believe is a lot cheaper to compute; but degenerate cases abound as you expand past the feature size (distances between nodes), so that by the fourth red ring it’s obviously incorrect.

Box shadows are another case where expansion occurs: the fourth length parameter, spread distance. If the corner is a cusp, the shadow corner will be a cusp. If it’s rounded, the shadow corner will be rounded. See https://drafts.csswg.org/css-backgrounds/#shadow-shape for some helpful diagrams. A sneaky trick: .1px border-radius means the box still looks square, but the expanded shadow will curve. Sometimes useful. But back on the original content of the article—if you use a font with microscopic curves instead of cusp nodes, Chromium/Safari will look more like Firefox.

by chrismorgan

5/6/2026 at 11:39:50 PM

There aren't many "corner" cases in Firefox :D

(Yes, it could technically be infinite corner cases)

by SpyCoder77

5/6/2026 at 12:36:27 PM

While I don't entirely love the rounding effect of firefox, I feel Chrome interpretation is just wrong in creating spurious spikes. Intuitively for the asterisk shape I'd expect the outline to go towards a plain hexagon, something that neither browser accomplishes.

by zokier

5/6/2026 at 4:02:45 PM

Miter join (Safari) VS round join (Chrome)

by mfabbri77

5/6/2026 at 11:59:31 AM

firefox looks like an SDF (shortest distance to the object), I'm not sure what the chrome one is...

by voidUpdate

5/6/2026 at 12:35:48 PM

I would assume they are just drawing the outline, not performing any distance calculations, and the differences are just a result of different linejoin choices. [1]

[1] https://www.w3.org/TR/fill-stroke-3/#stroke-linejoin

by danbruc

5/6/2026 at 1:43:29 PM

I'd imagine that at some point during the text rendering process, they have to generate an SDF of the text they want to render (it's what I did when I wanted to manually render text anyway). If they do, then they can generate the extra text-width lines basically for free, just fill everything with distance less than the property.

I may be entirely wrong though, I don't know in detail how browsers render stuff

by voidUpdate

5/6/2026 at 12:58:26 PM

Look at V in Love. It looks like bug in Chrome.

by npodbielski

5/6/2026 at 8:06:37 PM

The Firefox one looks like exactly what you’d expect from stepping the result of a SDF for that character. The rounded corners of the first layer would all be equidistant from the nearest corner of the original character.

by nkrisc

5/6/2026 at 5:00:35 PM

Ran into this discrepancy myself. On top that, what seemed also odd to me were the "dots" (tittle, period, semicolon) where oversized becomes hollow in the middle, like it cancels out itself. No other shape I've tried did that. And browsers surprisingly agreed on this.

Made few shots and playground for that back then: https://x.com/myfonj/status/1870178380831732160

by myfonj

5/6/2026 at 3:18:38 PM

I think Firefox applies more aggressive subpixel rendering and path smoothing before stroking. It resamples the glyph outline path at a higher precision level before handing it to the stroke algorithm.

by EMM_386

5/6/2026 at 1:07:07 PM

OT: really love the design of this blog. Simple, clear and content first.

by tiffanyh

5/6/2026 at 3:22:08 PM

Ya! So many posts with clear presentations of css/svg/canvas.

The Daily Sketch series or 'CSS Animation with offset-path' are equally fun.

by big_toast

5/6/2026 at 7:44:51 AM

Neat! It's unfortunate that the rendering is so different between browsers.

Have you tried the same thing with shadows? They can also be stacked, I believe.

by nicbou

5/6/2026 at 10:01:08 AM

Shadows have to be spread in a circle to achieve an outline, so the general shape will converge to roughly a circle, barely following the shape of the text.

by LoganDark

5/6/2026 at 7:27:23 PM

I just found out about https://css-doodle.com after reading that. A few months back, I was doing similar things with the HTML Canvas API. I didn’t know I could do these kinds of fun little things with CSS as well. Love that.

by eptityri

5/6/2026 at 5:36:52 PM

When I modified your fiddle to use the Apple logo and colors, the first ring is eating part of the apple. The top of the apple is cut off. Any idea why that is?

      --c: #5EBD3E,#FFB900,#F78200,#E23838,#973999,#009CDF;
      @content: '';

by joeframbach

5/6/2026 at 10:45:35 PM

I wonder what is the best way to do double stroked text without using fancy Unicode characters while still displaying what the font recommends. I currently use fancy characters on [my blog](https://blog.velocifyer.com/), but that harms search results. I am in the processes of migrating my blog to 11ty (from manual HTML) and I want to improve my blog at the same time.

PS: Please give me comments on the current design of the blog.

by Velocifyer

5/6/2026 at 6:57:54 PM

First thing I thought to do was add an emoji to the content. But it just shows the unknown char rectangle. I was hoping for magic, I guess.

by coneonthefloor

5/6/2026 at 7:25:18 PM

It works if you use Noto Emoji as the font.

by asibahi

5/7/2026 at 4:03:43 AM

An emoji rendered for me but not any of the outline stuff, just a bare emoji.

by herpdyderp

5/6/2026 at 7:59:59 PM

Eat your heart out Adobe Flash.

by nntwozz

5/6/2026 at 1:41:15 PM

This is so freaking cool

by vjay15

5/6/2026 at 3:07:59 PM

[flagged]

by jacktu

5/6/2026 at 8:51:55 AM

[flagged]

by shutterkiller

5/6/2026 at 10:33:05 AM

What's up with the bot accounts that just vaguely describe the article? Is it for karma farming accounts to sell on? I'm not opposed to bot accounts inherently but the stuff they so often post is just mind numbing to encounter, it feels like a little bit of my life has been stolen every time I get to the end of such a paragraph.

by AlecSchueler

5/6/2026 at 10:51:24 AM

Look up “generative engine optimization”

by peyton

5/6/2026 at 12:15:45 PM

Why are you not opposed to bot accounts? It is a terrible thing. People come here to read other people.

by svpernatvral

5/6/2026 at 10:53:06 AM

People should quit trying to make CSS a drawing tool--it is not--and start learning how to use SVG instead or images.

by assimpleaspossi

5/6/2026 at 12:04:26 PM

Art is often made from clever use of things that were not intended to make art. Let them have fun.

by wbobeirne

5/6/2026 at 12:49:23 PM

Too late: https://codepen.io/jaysalvat/pen/kazzOj

by emaro

5/6/2026 at 2:59:19 PM

A robust rebuttal. It’s how i prefer all of my images

by cdaringe

5/6/2026 at 9:26:29 PM

The HTML is invalid. <div id="monalisa" />

by assimpleaspossi

5/6/2026 at 1:57:55 PM

The article literally says "it's not well-suited for production usage" so I don't really see the reason for the objection here. It's an experiment.

by afavour

5/6/2026 at 11:18:24 AM

If you have a lot of "images" with such effects to generate from dynamic text, using SVG makes no sense, is vastly more complex and less flexible than the solution here.

by cafebabbe

5/6/2026 at 1:52:17 PM

You don't generate images, you just embed SVG nodes in the DOM. From the browser's perspective SVG and HTML elements are just two different types of element.

SVG is not great for text - HTML has more features - but for display text it's OK.

by zarzavat

5/6/2026 at 11:58:54 PM

I would rather have both working together:

My example: https://codepen.io/spartanatreyu/pen/xggjWz

------------------------------------------------

Overall, CSS tends to be the better tool for the job.

SVG has better paths and more interesting filters, but it's held back by a few critical issues.

1. A small amount of filters are not hardware accelerated in firefox/servo's webrender engine, which causes them to fallback to software rendering. Usually it just freezes the web page for a second or two while the image software renders before returning to normal performance, but if you try to animate any of the values it locks up the entire page.

That basically animated SVGs with filters a no-go.

2. Safari doesn't draw SVGs properly, it has a built-in "performance budget" where it just stops drawing the rest of the SVG if it isn't finished within a split second. Which is fine for something like an icon, but terrible for things like the main feature graphic / background of a page.

Meanwhile CSS keeps getting better. Its filters are improving (filter, mix-blend-mode, backdrop-filter), and its animations are improving too (keyframes + animation, transition, offset, custom-properties + @property's syntax, scroll-timeline, cross-document view transitions).

The two things that CSS is worse at than SVG are:

1. Paths (in which case, you can just put SVG paths into your page and style them with CSS for anything more complex than a static stroke/fill anyway)

2. Generating textures (which you can't guarantee look consistent thanks to Safari, so you're usually better off sending a hand optimized texture over the wire anyway)

by spartanatreyu

5/6/2026 at 2:00:13 PM

I would think that quite a few powerful new ideas have come purely from abusing and bashing around older ideas.

by mpalmer

5/6/2026 at 4:06:28 PM

It is pretty much the entire hacker ethos. "I have this thing that does something but not what I need, but with some tinkering it now does what I need" or even "I have this thing, but I'm just going to see what else I can make it do whether it is useful or not but solely because I can"

by dylan604

5/6/2026 at 3:46:58 PM

Probably writing itself was originally a hack.

by gblargg

5/6/2026 at 2:54:56 PM

I'd send you the link to the person who made a 3d renderer in pure CSS, with a very slow render of lara croft, but Cohost shut down

by voidUpdate

5/6/2026 at 11:14:56 AM

This could actually be cool for display text like a headline. I don’t think that’s only for images.

by echoangle