Validation

Free online text diff tool. Compare two texts in line, character or word mode with side-by-side or unified views, and live added/removed/unchanged counts. Runs entirely in your browser.

Free online regex tester. Live match highlighting, capture group extraction, replace preview and a built-in library (email, URL, mobile, ID, date). Runs entirely in your browser.

Free online crontab parser and generator. Standard 5-field syntax and common macros, a visual builder, and the next 5 run times computed in-browser. Runs entirely in your browser.

Free online JSON validator. Checks whether JSON is valid and reports its type and size. Parse errors are located to the exact line and column. Runs entirely in your browser.