Making Lottie Web Animations Accessible with Gatsby

tl;dr: I made a Gatsby Remark plugin that makes it easy to drop Lottie JSON animation files into your Markdown/MDX.

Over the past couple of weeks, I’ve been spending a lot of time in After Effects. We’ve been working on producing tutorial videos for Runly and I’ve taken it upon myself to do the motion graphics for the videos.

I’ve always dabbled with video editing and special effects in the past, but I’ve never had an excuse to use it for something real.

I generally don’t think of myself as one of the “creatives” but I’ve been having a lot of fun playing with motion graphics over the past few days. I’ve even watched three or four tutorial videos on YouTube, so naturally, I’m an expert now. Take a look at part of the intro I made:


Using After Effects Motion Graphics on the Web

You should go ahead and inspect that animation above. You may be wondering how I was able to render that animation without embedding a video or an animated GIF (or maybe you aren’t wondering and you already know — don’t get ahead of me).

Well, my dear internet friend, you can thank Lottie and her sister Bodymovin for bringing you that great animation.

When I first read that tweet, I had no idea what she was talking about. I thought these were all made-up words (I mean technically, that is true — all words are made-up). But, then I started to look into it and I discovered some cool stuff.

Apparently, if one is so inclined, one can make an animation in After Effects, export it to a JSON file (using the Bodymovin plugin), and then render it on the web as an animated SVG (using the Lottie JS package).

planets align

It seemed too serendiptious for me to stumble upon this tweet just as I was starting to get into motion graphics with After Effects. The planets just happened to align in my Twitter feed.


Check out Lottie Files for some animation inspiration.

Naturally, I immediately started playing with it and coming up with all sorts of reasons to use animated SVGs everywhere. Now that I have a new hammer, everything looks like a nail.

Performance of CSS Animations vs JS Animations

Before I get into it further, I hear some people in the back grumbling about animated SVGs aleady being a thing without needing to involve any JS scripts.

Well, dear peanut gallery, I implore you to read up on how JS animations outperform CSS animations written by people doing this web animation thing for longer than me. An animated SVG (without scripts) is using CSS to do its animations.

The gist is that JS animations are more better than CSS-animated SVGs. 🤷

Accessibility of Lottie Animations

One thing that started to worry me as I started to put animations in all the places was that maybe this wasn’t as accessible as I had hoped. Before the Lottie script loads to animate the SVG, the page is rendered with an empty container element:

<div id="myanimation"></div>

That kind of sucks. What about the poor search engines who go to index your site and don’t know what the hell that div is? Or what about the people who browse with JS disabled who will never see anything in that div (are there still people who do that in 2020)?

Ideally, I thought, we could follow the principle of graceful degradation and render a static SVG in that div for the search engines and the no-JS people. That way they would still have an idea of what was going on there — it just wouldn’t animate.

Enter Gatsby Plugin

I like using Gatsby due to the way it renders my React components ahead of time so that my site serves static HTML. After the site initially loads, a SPA is loaded on the client side to offer faster navigation and other perks. But, the site can work completely without JS.

Gatsby seems like a perfect fit to create a plugin that can take a Lottie JSON file and render it to a static SVG which is then “enhanced” with animation after the lottie-web script loads.

So, that’s exactly what I did. I created a Gatsby Remark plugin to allow you to easily drop Lottie JSONs into your Markdown/MDX which then generates “placeholder” SVGs which are animated after the fact.

Hi here is a cool animation:

![alt text](myanimation.json)

Wow, it’s so easy! No need to muck with the lottie-web scripts or worry about pre-rendering the JSON files to SVG. The plugin takes care of all of it for you! Wow, again! Much impress!

You can see it in action on this page by disabling javascript and scrolling around looking at the animations. With JS disabled, you should still see the static SVG as a placeholder.

Disable JS in Chrome
  1. F12 to open dev tools
  2. F1 to open dev tools settings
  3. Check Disable Javascript
  4. Refresh the page
  5. Bask in the static SVGs

Won’t you hop aboard the web animation rocket with me? There are so many places throughout the web that are dying for your animated touch.

What’s the use case for this?

I think where this web animation stuff really shines is in interaction design. With lottie-web, you can make an animation start or stop in response to a user action (e.g. liking something on Twitter). Subtle uses like that can really enhance the overall user experience of your app.

Take a look at the Trogdor example I threw together to see how I was playing around with animating interactions in a not-so-subtle way.

I’m thinking this plugin is more useful when you want to capture your user’s attention in a subtle way with some “static” animation. e.g. maybe something like an animated 404 page:

404 space error

For interaction design, I think you would be better off integrating the lottie-web library directly. This plugin makes it easy to get the animations on the page, not so much making them interactive.

Like I said before, I’m new to this whole web animation thing. Let me know what you think on Twitter. Follow me @wchadly while you are there for more content like this.