Orca is an open-source, extensible screen reader and screen magnifier for Linux operating systems.
Designed by the Sun Microsystems Accessibility Program Office, Orca is completely free. It’s also fairly powerful, which makes it an excellent tool for web developers who work in GNOME (GNU Network Object Model Environment) desktop environments.
You can download Orca by visiting the GNOME Project’s Orca page. However, before you use the software for screen reader testing, you should understand its features and limitations. As part of our series of articles on screen readers, we’re providing a quick overview of Orca’s capabilities.
Why Orca Screen Reader is Important for Linux
Like most Linux-specific software, Orca has a limited audience. JAWS (Jobs Access With Speech), NVDA (NonVisual Desktop Access), and Apple VoiceOver are the most commonly used screen readers, and Orca is much less popular.
However, Orca fills an important niche. While it isn’t the only Linux screen reader, it’s one of the most powerful and flexible options.
The major advantages of Orca:
It’s free, open-source software.
It enables non-visual access to standard applications in GNOME Desktop, though support may vary for non-standard applications.
It supports braille output and has built-in screen magnification with automated focus tracking.
It’s customizable, with several default voices and controls for rate, pitch, volume, and verbosity (verbosity is the amount of info that the screen reader outputs about each focusable element).
Can I use the Orca screen reader to test website accessibility?
If you’re working on Linux, it makes sense to test web content for screen reader accessibility with Orca — but remember, your experience will be limited.
Like other desktop screen readers, Orca’s output can vary depending on the user’s preferences and web browser. Testing a website with Firefox, Chrome, or Opera may yield completely different results.
Additionally, if you’re unfamiliar with screen readers, you may feel overwhelmed by Orca’s controls. Even if you take the time to learn the hotkeys, you probably won’t have the proficiency of a regular screen reader user — you might identify accessibility issues that don’t exist, or alternatively, you may miss barriers that a more experienced Orca user would notice.
With that said, we believe that every developer should spend some time with a screen reader. Using assistive technology can help you develop an inclusive mindset, and since Orca is free, it’s an excellent tool for basic testing.
Tips for Reviewing Web Content with Orca Screen Reader
No two screen readers work exactly the same. Orca supports WAI-ARIA (Web Accessibility Initiative - Accessible Rich Internet Applications), but it may output information differently than NVDA or JAWS.
Tips to keep in mind when testing content with the Orca screen reader:
Read Orca’s documentation before using the software. Keep a reference list of hotkeys nearby as you test.
Many Orca commands use a modifier key, which is CapsLock by default on its laptop layout. On Orca’s desktop layout, the default modifier will be both Insert and KP_Insert.
Review Orca’s preferences and make any necessary changes before opening your web browser.
For accessibility testing, you should choose a moderate level of verbosity, which will enable Orca to describe semantic information about each on-page element.
As you browse your website, pay attention to images, videos, forms, and interactive controls. Does everything make sense? Can you navigate easily, or is the screen reader’s output confusing?
Try to use the keyboard alone (with no mouse). Do you understand which element has focus? Does your content contain any keyboard traps?
Finally, avoid drawing broad conclusions about the accessibility of your content. If you encounter a barrier in Orca, you may need to verify that the problem exists by testing with other screen readers. In other words: Don’t assume that you can thoroughly test your website with Orca alone.
Remember, digital accessibility isn’t just for people with vision disabilities, and no single test can guarantee conformance with the Web Content Accessibility Guidelines. The Bureau of Internet Accessibility recommends using a combination of automated and manual evaluations to find and remediate accessibility barriers.