The ARC Toolkit is an accessibility extension for Firefox designed specifically for developers. This subscription-based tool facilitates both automated and manual testing of web applications, ensuring compliance with WCAG standards. It integrates smoothly with Firefox's Developer Tools, providing an interactive panel that displays test results directly on the web page, enabling developers to toggle tests and delve into specific accessibility issues with ease.

Key features of the ARC Toolkit include its operation within the browser, compatibility with iframes, and support for testing in development environments through file URLs. The toolkit employs predefined rules aligned with ARC platform testing, which guarantees reliable identification of accessibility concerns. Regular updates further enhance its capabilities, making it an essential resource for developers and quality assurance testers dedicated to improving web accessibility.