Wave (accessibility tool) is described as 'WAVE is a visual web accessibility analysis tool that evaluates web accessibility based on the Web Content Accessibility Guidelines (WCAG)' and is an app in the OS & Utilities category. There are seven alternatives to Wave (accessibility tool) for a variety of platforms, including Online / Web-based, Mac, Windows, Linux and Self-Hosted solutions. The best alternative is Koa11y, which is both free and Open Source. Other great apps like Wave (accessibility tool) are Who Can Use (Free, Open Source), Colour Contrast Analyser (Free), EIII checker suite (Free) and Palette for Mac (Free).
Koa11y is a cross-platform desktop application for finding accessibility issues on public web pages. Simply enter a page's url and the select the standards format (Section 508, WCAG 2.0) and click Run. The app generates an HTML page detailing test results.
Colour Contrast Analyser allows you to evaluate the color visibility and contrast of foreground/background color combinations. It provides an initial pass/fail assessment against WCAG 2.0 color contrast success criteria.
Palette provides a super simple way to analyze colors across RGB, #HEX and CSS formats. Try it online for free or download it for macOS with a donation-based download where you pay what you want (even $0 to try it).