KA Engineering

KA Engineering

We're the engineers behind Khan Academy. We're building a free, world-class education for anyone, anywhere.


Upcoming fortnightly post

Migrating to a Mobile Monorepo for React Native

by Jared Forsyth on May 29

Latest posts

Memcached-Backed Content Infrastructure

Ben Kraft on May 15

Profiling App Engine Memcached

Ben Kraft on May 1

App Engine Flex Language Shootout

Amos Latteier on April 17

What's New in OSS at Khan Academy

Brian Genisio on April 3

Automating App Store Screenshots

Bryan Clark on March 27

It's Okay to Break Things: Reflections on Khan Academy's Healthy Hackathon

Kimerie Green on March 6

Interning at Khan Academy: from student to intern

Shadaj Laddad on December 12

Prototyping with Framer

Nick Breen on October 3

Evolving our content infrastructure

William Chargin on September 19

Building a Really, Really Small Android App

Charlie Marsh on August 22

A Case for Time Tracking: Data Driven Time-Management

Oliver Northwood on August 8

Time Management at Khan Academy

Several Authors on July 25

Hackathons Can Be Healthy

Tom Yedwab on July 11

Ensuring transaction-safety in Google App Engine

Craig Silverstein on June 27

The User Write Lock: an Alternative to Transactions for Google App Engine

Craig Silverstein on June 20

Khan Academy's Engineering Principles

Ben Kamens on June 6

Minimizing the length of regular expressions, in practice

Craig Silverstein on May 23

Introducing SwiftTweaks

Bryan Clark on May 9

The Autonomous Dumbledore

Evy Kassirer on April 25

Engineering career development at Khan Academy

Ben Eater on April 11

Inline CSS at Khan Academy: Aphrodite

Jamie Wong on March 29

Starting Android at Khan Academy

Ben Komalo on February 29

Automating Highly Similar Translations

Kevin Barabash on February 15

The weekly snippet-server: open-sourced

Craig Silverstein on February 1

Stories from our latest intern class

2015 Interns on December 21

Kanbanning the LearnStorm Dev Process

Kevin Dangoor on December 7

Forgo JS packaging? Not so fast

Craig Silverstein on November 23

Switching to Slack

Benjamin Pollack on November 9

Receiving feedback as an intern at Khan Academy

David Wang on October 26

Schrödinger's deploys no more: how we update translations

Chelsea Voss on October 12

i18nize-templates: Internationalization After the Fact

Craig Silverstein on September 28

Making thumbnails fast

William Chargin on September 14

Copy-pasting more than just text

Sam Lau on August 31

No cheating allowed!!

Phillip Lemons on August 17

Fun with slope fields, css and react

Marcos Ojeda on August 5

Khan Academy: a new employee's primer

Riley Shaw on July 20

How wooden puzzles can destroy dev teams

John Sullivan on July 6

Babel in Khan Academy's i18n Toolchain

Kevin Barabash on June 22

tota11y - an accessibility visualization toolkit

Jordan Scales on June 8


tota11y - an accessibility visualization toolkit

by Jordan Scales on June 8

Today we're releasing tota11y (on GitHub), an accessibility visualization toolkit that aims to reduce the friction of a11y testing.

tota11y logo


Accessibility is hard for many reasons. While current tooling provides mechanisms for detecting most accessibility violations, there remains a certain amount of disconnect between the developer and the problems they are causing. Most of these errors are things we can't see, things that won't affect us, and things without a perfect, exact fix.

tota11y aims to solve these problems by providing a fun, interactive way to see accessibility issues. Not only should the web be fully accessible to all, but developers should feel empowered to fix and prevent accessibility violations from happening in the first place.

A bit of history

We've been explicitly working to improve the accessibility of Khan Academy since early January. In that time we've seen first hand what it takes to go through each and every page on our website and fix things that may prove to be troublesome to assistive technologies.

John and I were both very new to this, so we set out and did our research, wrote some tests to detect violations using Chrome's Accessibility Developer Tools, and got to work.

A few weeks later we had fixed a significant chunk of accessibility errors on our site, and learned an immense amount about assistive technologies.

Chrome's Accessibility Developer Tools reporting some errors on our homepage

Then the hard part came.

We felt capable of fixing most accessibility violations on our site, but how could we spread that knowledge to the team efficiently? How could we make every Khan Academy employee feel empowered to report and fix accessibility violations?

We gave talks, wrote docs, sent out emails, but regressions still popped up. Our tests ran, but were flaky, and didn't gain the same level of respect as our unit tests or linter.

Simply put, our dev team still didn't fully understand the problems they were causing, and how to fix them.

Meet tota11y

About a month ago we set out to build tota11y as an internal project for Khan Academy's "Web Frontend" team.

The aim was to make it as simple as possible for developers to do manual accessibility testing as part of their normal work. Rather than requiring our dev team to dig through long-winded audit reports for violations they didn't understand, we wanted provide simple visualizations where they already were - the browser, right in front of them.

So we started off with the idea of "annotations." We highlight parts of the current document, either to point out errors, successes, or just to label important tags like headings or ARIA landmarks.

An early tota11y demo showing heading annotations

A (very) early proof-of-concept for tota11y.

We ran with this core idea of "annotations" and expanded it, as you'll see, to include detailed error messages, suggestions for fixes, and more.

What can tota11y do

tota11y is a single JavaScript file that you can include in your document like so:

<script src="tota11y.min.js"></script>

Once you see the glasses in the bottom left corner of your window, you're good to go.

The collapsed tota11y toolbar, a small button with a glasses icon

tota11y currently includes plugins for the following:

  • detecting images with/without alt text (and presentation images)
  • labeling text with contrast violations (and suggesting appropriate color combinations)
  • outlining a document's heading structure and pointing out any errors with it
  • highlighting input fields without appropriate labels (and suggesting fixes based on context)
  • labeling all ARIA landmarks on the page
  • detecting unclear link text such as "Click here" and "More"

Many of these come directly from Google Chrome's Accessibility Developer Tools.

The expanded tota11y toolbar displaying a list of plugins

Some plugins (like the landmarks plugin) are as simple as labeling parts of the page.

tota11y highlighting aria landmarks on wikipedia.org

Others provide an extended summary of the page, like the headings plugin, using what's known as the "info panel."

tota11y highlighting heading tags and structure on wikipedia.org

Also using this info panel, we can report errors in more detail and offer suggestions.

tota11y explaining contrast violations and offering suggestions on github.com

While we can't guarantee to solve all of your accessibility troubles, we think this approach makes violations easier to digest and will inspire developers to think differently about accessibility.

What's in store?

We want to see how others use tota11y, and figure out what other sorts of accessibility violations we can help fix. Some ideas include:

  • proper/improper usage of the "tabindex" attribute
  • improper disabling of focus styling
  • buttons that are not keyboard-accessible

We also want to continue building a solid API for tota11y, enabling developers to write their own tota11y plugins which may not be included in the original source.

And we're planning on bundling tota11y as a series of browser extensions to make it easier to test websites without the need to include a script in your application.

We hope using tota11y makes you feel empowered to spot, diagnose, and fix accessibility issues on your webpages. Be sure to check us out on GitHub and let us know how we can help.