To identify the majority of your accessibility issues, try exploring your product with a screen reader program or a screen reader emulator/simulator like Silktide. For the best results, use an actual screen reader program and choose one that is more commonly used by persons with disabilities. We've listed a number screen reader programs for different operating systems and platforms below and provided links to their documentation. For your convenience, we've also arranged the list from most used at the top to least used at the bottom, according to data from WebAIM's annual survey results for 2019.
Before starting your screen reader, learn how to turn the screen reader on and off. If you are annoyed by the voice or are startled by how loud the voice is, you will want to be able to quickly turn it off.
Afterward, determine your screen reader's modifier key (a key or combination of keys that are held down while other commands are entered). JAWS and NVDA have Insert as their modifier, although NVDA can be set to use Caps Lock. VoiceOver uses Caps Lock or Ctrl + Option as its modifier.
To begin exploring with a desktop computer or laptop, set your mouse aside or turn it off then start using the Tab key, Shift + Tab keys, and the directional arrow keys (← → ↑ ↓) to navigate. Depending on your screen reader, some of these navigation commands may require that the modifier key(s) be pressed before the navigation occur. Additionally, some web tools (especially Adobe's tools and a number of web conferencing tools) may also require the use of the F6 key to navigate from panel to panel. To activate links or buttons, you will generally use either the spacebar or the enter key.
To begin exploring with a touchscreen device, swipe left or right and then double-tap to activate.
As you explore, pay attention to reading order; verbalization of graphics; and the ability to access, activate, and/or exit every feature. If you cannot reach, activate, or exit a feature through the screen reader's commands or gestures, check that the product you're exploring doesn't have specific commands for doing so. If it does not, then there is a strong probability that you have discovered an accessibility issue that needs repair. Additionally, if you do not have a visible indication for where you are in the product as you navigate (i.e. a "focus ring") then this too is an accessibility issue.