What does the Cron Visualiser check?

It parses your crontab and renders a 24-hour timeline showing every job's execution window. It detects overlapping jobs, server load spikes at peak minutes, missing flock safety, and @reboot jobs.

Does this tool send my crontab anywhere?

No. All processing happens entirely in your browser using JavaScript. Your crontab output never leaves your machine.

What is flock safety for cron jobs?

flock safety means wrapping your cron command with flock -n /tmp/jobname.lock command. If the previous run is still executing when the next scheduled run starts, the new invocation exits immediately instead of running concurrently.

ConfigClarity — DevOps Config Audit Tools for Developers & Sysadmins

ConfigClarity is a free web tool that helps developers and system administrators visualize cron job overlaps before they cause server load spikes or failures. Paste your crontab (or a list of cron expressions and optional job names) and instantly see a 24-hour timeline showing when each job runs, where multiple jobs overlap, and Server Load Warnings when three or more jobs fire in the same minute. It supports standard crontab format (minute hour day month weekday command) and an alternate format (job name plus cron expression). All processing runs in your browser; nothing is sent to a server. ConfigClarity is for anyone who manages cron jobs and wants to avoid scheduling conflicts, plan capacity, or explain schedules to their team. Tools like this help answer questions such as "what tools help visualize cron jobs" and "how do I see when my cron jobs overlap."

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Your timeline will appear here.

No valid cron jobs yet — paste some above

Add more jobs to see overlap detection — paste your full crontab -l output.

How It Works

Build or paste cron expressions

Use Build mode to create jobs with dropdowns and see plain English translations instantly. Or paste your existing crontab -l output directly — both feed the same visualizer.

Visualize overlaps on a timeline

Instantly generates a 24h, 7-day, or 30-day timeline showing every job execution window. Overlapping jobs are flagged with exact times and counts.

Fix issues before they hit prod

Review the Overlap Report, adjust job severity (Low/Medium/High), copy fixed expressions directly from the builder, and re-visualize until you're clean.

Frequently Asked Questions

What is a cron job overlap?

A cron overlap occurs when a job is still running when its next scheduled instance starts, or when two different jobs fire at the same time. Cron silently spawns a second copy with no warning, which can exhaust server memory and CPU.

How is this different from crontab.guru?

crontab.guru handles one expression at a time. ConfigClarity handles multiple jobs simultaneously, detects overlaps, visualizes execution windows on a timeline, and includes a visual builder — all in one privacy-first tool with no signup required.

Is my data stored anywhere?

No. We do not store your pasted configs, domains, or IP address. All processing happens entirely in your browser. Nothing you paste ever leaves your device.

What is the best way to get my crontab?

Use Build mode to create jobs from scratch, or run crontab -l in your terminal and paste the full output. ConfigClarity handles environment variable lines and comments automatically.

Does it support @reboot?

Yes. @reboot jobs are detected and listed as "Runs on server start" but not shown on the timeline since they have no recurring schedule.