Chrome Developer Tool
Lighthouse
GitHub
LaunchKit - Open Source
WCAGCheck.app
Codefield
Wave
Web.dev by Google
kdiff3
Beyond Compare
WinMerge
Meld
Araxis Merge
DiffMerge
P4Merge
Devart Code Compare
kdiff3Lighthouse - Collaborate effortlessly on projects. Whether youโre a team of 5 or studio of 50, Lighthouse will help you keep track of your project development with ease.
Beyond Compare - Beyond Compare allows you to compare files and folders.
GitHub - Originally founded as a project to simplify sharing code, GitHub has grown into an application used by over a million people to store over two million code repositories, making GitHub the largest code host in the world.
WinMerge - WinMerge is an open source differencing and merging tool for Windows.
LaunchKit - Open Source - A popular suite of developer tools, now 100% open source.
Meld - What is Meld? Meld is a visual diff and merge tool targeted at developers.