Koa11y is a free open source desktop app for Linux, mac and Windows that allows you to automatically detect accessibility or a11y issues on your webpages. It finds accessibility problems like missing image Alt attributes, color contrast issues, missing titles, lengthy ALTs and poorly designed forms. Koa11y supports WCAG2AA, WCAG2A, WCAG2AAA and Section 508 Web Content Accessibility Guidelines to validate your website.
The windows and Linux versions are portable program and no need to install. Just download, unzip and run the app.
You can also control the output format and output location. The default format is html file. The UI is very simple. Just enter your website page url and select output format and filename. And click the RUN button to export the results.