Build or explain a cron expression

Developer tools in one place: regex tester, cron expressions, JWT decoder/verifier, SQL formatter + SQLite; JSON & XML (validate, format, tree, compare, sitemap), UUID & Unix time, text diff & syntax highlighting, screen & responsive checker and a website SEO checker.

Updated November 9, 2026

Developer tools

• Format JSON
• Test a regex
• Format SQL / SQLite playground
• Generate a UUID
• Convert Unix time
• Compare two texts
• Check a site’s SEO
• Developer tools →