My name is Mat “Wilto” Marquis, and I make websites.

I’m an independent consultant. My specialization is inclusive web development.

My goal is to ensure that your content can reach any user, in any browsing context—regardless of the size of their screen, the speed of their internet connection, the age of their device, or the combination of browsers and assistive technologies they use to experience the web.

If you have the same goal, we should chat.

I’ve helped build some websites.

Screenshots of,,, and in illustrated generic device frames.

I’m a developer that heavily skews “designer.” From design to implementation, I believe that a good layout is a flexible, durable, and maintainable one.

I’ve been brought in to help clients like Rolling Stone with their performance concerns, clients like Axios and Microsoft with their accessibility concerns, and clients like ProPublica and Amazon’s PillPack to build, maintain, and improve on their websites.

Responsive Web Design

I’m incredibly fortunate to have played a small part in the history of Responsive Web Design, from the earliest discussions of the responsive Boston Globe project—all the way back in 2011—to leading the effort to add responsive image features to the HTML specification, browsers, and major CMSes.

Front-End Performance

I’ve had the privilege of traveling the world speaking about front-end performance. I’ve worked with organizations large and small not just to audit, identify, and help fix their performance pain points, but to establish workflows, development habits, and support systems that allow those improvements—and their results—to persist long after I’m gone.


I firmly believe that accessibility isn’t an add-on, a line item, or an ticket languishing in an issue tracker for “if we have time at the end.” It’s a persistent consideration through every step in the creation of a site—from content, to wireframes, to markup, to the final product. In the years that followed my accessibility work on the jQuery UI and jQuery Mobile teams, I’ve helped guide a number of organizations through the process of prioritizing accessibility both technically and culturally.

I do a lot of writing.

Covers of the books Image Performance and JavaScript for Web Designers, side by side.

I wrote JavaScript for Web Designers a few years ago, now. It’s paced for anyone taking their first steps into the world of JavaScript development, but in-depth enough for anyone looking to understand JavaScript’s inner workings.

I wrote Image Performance just last year. It’s a deep-dive into a subject that’s easy to take for granted, but difficult to master: putting images on the web. It covers everything from the inner workings of image formats and compression methods to responsive image markup to automation.

Before writing two books of my own, I wrote the Robust, Responsible, Responsive Web Design chapter of Smashing Book 4, and two chapters on JavaScript for the fourth edition of Jennifer Robbins’ Learning Web Design.

Fingers crossed, maybe someday I’ll add a cookbook to the list.

I want to build a better web.

Me, I’m stubborn. If it can be done on the web, I believe that it can be done responsively, it can be done accessibly, and it can be done in a performant way—it can be made to work for everyone.

The trickier that might seem at first, the more you’ve got my attention.

Those are the kind of projects I’m interested in—not just because that’s the sort of impact I want to make on the web, but because that’s where the exciting work is. That’s the space where we get to invent new approaches and techniques; to build something brand new together, in pursuit of making the web a faster, more welcoming, and more inclusive place.

If it sounds as though I might be a good fit for your next project, don’t hesitate to get in touch. I’m looking forward to it.

I’m here to help.

Listen, it’s hard out there—for our friends, our families, our neighbors, and many of us. If you’re here to help people, I’m here to help you.

If your organization is working to help those in vulnerable positions and you could use an extra set of website-making hands, I’ll work with your budget and your schedule to make it happen.

Office Hours

If your non-profit could use an on-the-fly accessibility audit, quick tips for speeding up your website, a second opinion on a particularly thorny browser issue, or general advice about the web, how it’s built, and how to hire the people that build it: you’re welcome to my time, whenever it’s convenient for you and your team.

We’re all in this together.

I keep busy.

I’ve been a speaker at conferences like An Event Apart and Smashing Conference, and an emcee for Confab. I’m an amateur boxer, aspiring chef, halfway decent carpenter, passable antique British motorcycle mechanic, and wannabe gardener.

I’ve even been in a movie—What Comes Next is the Future—to discuss the role I played in web standards, and how I hoped to change them. I’ve got an IMDB page and everything!

Just—… just ignore the other thing on there.

It’s a long story.