Photosensitive Epilepsy should be a concern to anyone creating any type of animated media. As a matter of fact, in order to pass WCAG Level A, a web page cannot “contain anything that flashes more than three times in any one second period, or the flash is below the general flash and red flash thresholds”. Testing this requirement may seem a little daunting at first, but luckily there is a free tool called PEAT that web developers can use to test if their animations and videos can cause an epileptic attack. This blog post talks about how to use PEAT, what it’s limitations are, and how to work around them.

Placeholder text is used quite a bit in modern HTML5 forms. It is not meant to replace form labels, but is intended to be a hint about the format of what the form field data should take. While checking the accessibility issues on a recent project, I noticed that placeholder text is sometimes indistinguishable with form field values when using certain screen reader/browser combinations. This post talks about how to work around this issue with just a little bit of JavaScript.

Firefox, unlike every other browser on the planet, changes the way that keyboard navigation works in designs that use the CSS order property. Since a lot of developers use flexbox, this can create a lot of cross-browser accessibility issues. This article shows a fix for this problem using a small amount of Javascript.

One of the most common and straightforward accessible features of a web site is the “skip navigation” link. These links are intended to make it easier for users with screen readers to skip all the links in a webpage’s header navigation in order to read the content on the rest of the page. However, many developers don’t know all the tricks that are needed to use in order to implement one correctly. This article will go into this in depth.

Do you want the state of a web page to be rendered by both the client and the server side? Is having the state of a JavaScript rendered web page to be controlled by the page’s query string important to you? Is important for you to ensure that your page’s state can be shared correctly via email and social media? If you want all of this without being tied into any specific framework (e.g. React, jQuery, Angular, etc) and done using progressive-enhancement, read on.

The Firefox team has made some unique choices when rendering fonts in the Windows operating system. As a result, certain fonts under 16 pixels in size render really bad in HTML5 Canvas as well as CSS. This blog post shows how you can fix this issue and have clean, transformed typography in any OS.

PNGs with alpha channels are great, but they can take up a lot of bandwidth. Alternative image formats such as JPEG-XR, JPEG 2000 and WEBP are more efficient, but they are not supported by FIrefox (and may never be). In comes a full cross-browser solution: SVG files that encapulate a JPEG with an alpha channel. This post will cover how to create these image files a number of different ways, and show how you can animate these images as well.

Although .properties files are used to give multi-language support in JSP pages, they are not just restricted to Java platform — libraries exist for JavaScript, Ruby, Perl, Flex and a whole slew of other languages). When used in multi-developer environments, they can get rather messy and they can be rather translator unfriendly. In this article, you’ll see how you can quickly fix these issues with z4n, a set of shell scripts I created to manage .properties files and includes tools for developers to extract translation data from Excel spreadsheets. Read on, and I’ll show you how to keep .properites files sane for all your web projects.

It’s possible to super-impose dynamic HTML content on top of a photos using 3D transforms to give the appearance that it is part of the picture. However, using a combination of translate3d(), scale3d() and rotate3d() functions to do this is difficult. This article discusses how to use the matrix3d() CSS transform with the Matrix Construction Set to get pixel-perfect 3D transforms easily and without any knowledge of matrix arithmetic. It also discusses the differences between matrix() and matrix3d(), as well as what fallbacks to use for browsers that don’t support transforms.

WEBP, JPEG 2000, JPEG-XR, APNG … these image formats have features that are not available in the traditional GIF/JPEG/PNG/SVG image stack, like animation, lossy compressions paired with alpha channels and better quality at higher compression levels. However, each browser seems to support only some of these formats. With the <picture> element, along with the picturefill polyfill, you can use these great formats today while using the older formats for an old-fashioned fallback. This blog post will explain how to use picturefill or modernizr to use these formats, why you would want to use these image formats, and what tools you can use to generate them.