Validate cron schedules and preview next run times — catch the Sunday-vs-7 bug before production. Verify 0 2 * * * runs 2am daily — local parsing, free, no signup.
Content reviewed October 2026 · About Toolzum
Parse cron expressions into human-readable descriptions. Includes common presets for quick reference. Presets plus plain-English schedules prevent 3am surprises — local parsing, free, no signup.
Validate package.json for required fields, semver format, and dependency presence. Catch missing fields and bad semver before installs fail — free, local, no signup.
Validate robots.txt syntax — user-agents, allow/disallow, sitemaps, wildcards. Catch the Disallow: / that deindexed everything — local validation, free, no signup.
Validate IBAN structure, length, and mod-97 check digits for 80+ countries. Catch transfer typos before money moves — local ibantools work, free, no signup.
Validate CSV structure — flag rows with wrong column counts and empty cells before import. Catch bad rows locally — free, no signup.
Minute hour day-of-month month day-of-week: 0 2 * * * runs 2am daily. Both day fields set means OR in most implementations — the classic scheduling surprise.
Day-of-week 0 and 7 both mean Sunday in most crons, but some accept only one. The preview lists actual next runs — empty means the expression never fires.
@daily, @hourly, @reboot where the implementation allows — the validator flags unsupported shorthands per target.
No — parsing runs locally in your browser. Nothing leaves your device.