Fractal: HTML and CSS Email Validator

Building a website takes a lot of work. One of the most tedious aspects of it is making sure it displays correctly across multiple browsers. The well known browser wars have long been the bane of web developers. Despite efforts to standardize, each has its own implementation details that you need to learn.

This problem is exacerbated in the little thought about rendering of HTML within email. HTMLized emails look great and provide a mini webpage for those that receive them. The trouble is that email clients have even greater disparities in their support of HTML and CSS. In general email clients support less functionality than a full fledged browser. The question is, how much less? As is turns out there’s great variance across the major email clients. This creates an even bigger challenge for developers than for web pages.

Fractal Home

To address this people finally got smart and developed email client standards. These at the very least establish a protocol that all mail clients will be held to. Their so called Acid test outlines what tags should be supported and how they should be rendered. This is all well and good, but providers will invariably deviate from any protocols that are set. It’s for this reason Fractal was built. It’s an HTML and CSS code validator that will check your code against 24 email clients. This will tell you definitively whether your recipients will be able to view your emails correctly.

Working with Fractal, (found at, is easy. Simply copy and paste your code into the text box and press the “Let’s do this” button. If everything checks out you’ll receive a nice message indicating that you’re all set to go. If not then you’ll receive a detailed summary of the issue. Fractal’s results are actually extremely useful and well written. It not only indicates the elements that aren’t supported but also the line number. Further, it tells you which email clients don’t support it including both web and mobile versions. It will also tell you which platforms partially support it. And if that wasn’t enough, they also offer suggestions for how to remedy the issue. If all error and code checking tools did this then our lives would be much easier.

Fractal Compatability Summary

Fractal’s free service is an extremely useful way to validate one’s HTML for emails. In a matter of seconds you can find out if there are any issues and exactly what they are. Its suggested solutions to incompatible elements can save developers and marketers lots of time in trying to find alternative ways to accomplish the same thing. I’m going to go out on a limb and surmise that this tool was built out of the frustration of having to resolve such differences manually. If a developer does that enough they eventually get smart and build a tool to fix it. However it came to pass, the folks behind Fractal did get smart and provided a robust HTML and CSS compatibility testing tool for all the major email clients.