Testing your site for keyboard navigation will help ensure that keyboard users can access your site.
As a bonus, sites that can be navigated with a keyboard are more likely to be navigable with other input devices such as switches.
How to navigate a website with a keyboard
Generally, pressing tab moves focus between interactive elements and pressing enter will interact with them.
If you are using Safari, option-tab is the default keyboard shortcut to move focus between elements. You can update your settings to make tab the default navigation key by following the instructions in this article: Quick Tip: Safari Keyboard Navigation
Additional keyboard shortcuts are described here: WebAIM - Keyboard Accessibility
Things to keep in mind while testing
It is not enough to simply tab through a webpage from start to end. While navigating the site, keep these things in mind:
- Interactive elements should be functional using only keyboard input.
- The focused element should be visible and have an obvious focus style. See article: “Quick Tip: Never remove CSS outlines”.
- Focus should move between elements as they appear on the page and not jump back and forth.
- There should be a way to skip past lengthy spans of content, like global navigation menus. See article: “How–to: Use Skip Navigation links”.
- WebAIM - Keyboard Accessibility
- Nielsen Norman Group - Keyboard-Only Navigation for Improved Accessibility
- User Testing - Why Keyboard Usability Is More Important Than You Think