About Us

It’s unmistakable that the world has a greater reliance on the web and online services. This demand means that equal access to information for all is more critical than ever before. Chax is here to help.

Group photo of the Tamman/Chax team.

A Culture of Learning


Our “people first” philosophy prioritizes professional development, fostering a culture of learning to stay aligned with evolving industry standards. This commitment enables us to deliver the most inclusive programs, products, and solutions.

Our dedication to inclusivity and professional growth laid the foundation for Chax’s evolution. In 2022, Chad Chelius and Dax Castro founded Chax after many years of independent consulting and training. At the end of 2023, Chax merged with Tamman, forming a global leader in accessibility services with a combined team of dozens of experts, many certified by the IAAP or Trusted Testers, and expanded our robust internal training program. Chad and Dax are both IAAP-certified document specialists and Adobe-certified trainers. Together, together with over a dozen additional accessibility subject matter experts, we bring decades of experience, keeping accessibility at the forefront of our work.

Our Origin Story


Dax Castro: You know, I got started in accessibility because I worked on the California High Speed Rail Project, and I was a presentation designer. And so my job was to create PowerPoints and slide decks and animations and videos for different parts of the high speed rail. And I also knew InDesign.
And so somebody knocked on our door one day and said, “hey, we need you to start making all of our content accessible. Who knows anything about that?”
And I was like, “I don’t, but I can learn!” And I went home that night and learned all I could. And honestly, it just was the spark that I needed to start the fire to what has now become, you know, pretty much a life career. And I just, you know, couldn’t be more happy about having that opportunity, which was just a knock on the door.

Chad Chelius: You know, I think a lot of people want my answer to be that I have a relative or a personal connection that got me into accessibility, but the reality is I was speaking at a conference down in Florida, late 90s, and I was talking about the PDF format and all the cool things you can do with the PDF format, and there was a lady in the back of the room who raised her hand and she said, “That’s all great, but is it accessible?”

I had no idea what she was talking about.

Her and I ended up becoming really good friends, and she started telling me about accessibility and the idea that PDF files can have this tag structure that is read by assistive technology and and to be honest, I was just fascinated by it, like the idea that we had this underlying structure and And I could impact the lives of of people with disabilities by making a change in how I worked really made a huge impact on my career.
At first it was more just out of curiosity, but as time went on, all of a sudden people started reaching out to me and wanting to know more about accessibility, and that’s how my career kind of bloomed and how I ended up in accessibility today.

Dax Castro: You know, one of the reasons I love accessibility in the field of accessibility is really it’s about helping people. I wanna help people who are struggling to learn how to do document accessibility, and I wanna help the end user have a better experience when they open that document up.
It is really the connection about creating accessible content in a world full of inaccessible things and if I can improve that person’s life for that one document, I feel validated.

Chad Chelius: What I do can impact so many people’s lives. We are now acknowledging people with disabilities more and more.
As part of that acknowledgement, we need to put our money where our mouth is. Dax and I, we don’t let anything go out the door unless it’s accessible, and if we put something out there that’s not accessible, we’re not practicing what we preach.
That’s fundamentally why we believe so strongly in what we do.

Chad Chelius: Accessibility is so important in today’s society because it really connects us. The idea of our cell phones and the Internet, it’s a part of our daily lives. It’s woven into everything that we are and as a society it’s important that we don’t marginalize any community.
If you have access, you feel included. We wanna make sure that everyone’s included in today’s society.

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