Free Cron Parser API — Convert Cron Expressions to Human-Readable Text

"What Does 0 */6 * * 1-5 Mean Again?"

If you've ever stared at a crontab entry trying to decode it, you're not alone. Cron expressions are powerful but cryptic.

Cron Parser API

A free REST API that turns cron expressions into something humans can actually read.

Parse & Explain

curl -X POST "https://cron-parser-api.p.rapidapi.com/parse" \
  -H "Content-Type: application/json" \
  -d '{"expression": "0 */6 * * 1-5"}'

Response:

{
  "expression": "0 */6 * * 1-5",
  "description": "At minute 0, every 6 hours, Monday through Friday",
  "valid": true,
  "fields": {
    "minute": "0",
    "hour": "*/6",
    "dayOfMonth": "*",
    "month": "*",
    "dayOfWeek": "1-5"
  },
  "nextRuns": [
    "2026-04-08T12:00:00Z",
    "2026-04-08T18:00:00Z",
    "2026-04-09T00:00:00Z",
    "2026-04-09T06:00:00Z",
    "2026-04-09T12:00:00Z"
  ]
}

Validate

Check if a cron expression is syntactically valid before deploying:

curl -X POST ".../validate" -d '{"expression": "60 * * * *"}'
# → {"valid": false, "error": "Minute field: 60 is out of range (0-59)"}

Supported Formats

• 5 fields: Standard cron (minute hour dom month dow)
• 6 fields: With seconds (AWS EventBridge, Quartz)
• 7 fields: With year (Quartz)

Real-World Use Cases

• DevOps dashboards: Show "runs every 6 hours on weekdays" instead of raw expressions
• CI/CD: Validate cron schedules in GitHub Actions / GitLab CI before push
• Admin panels: Let non-technical users understand scheduled tasks
• Documentation: Auto-generate human descriptions of cron jobs

Free Tier

• 200 requests/month, no credit card
• Sub-50ms globally (Cloudflare Workers)

Try it free: Cron Parser API on RapidAPI

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Part of my 46 free developer APIs. All running on Cloudflare Workers free tier.