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Setting up an IONOS cronjob and when a second route helps

IONOS ships a usable cronjob management that can call scripts via the command line or by address. There are two things it cannot do, and that is what this guide is about.

Why at all

Where the built-in solution reaches its limit

In its own help centre IONOS recommends letting at least five minutes pass before a cronjob runs again. The reasoning is sound: with a call every minute, runs can overlap and block the server. But anyone who genuinely needs a one-minute interval, for example for a shop's action scheduler, faces a recommendation working against them.

The second point is traceability. A scheduler at your host generally does not tell you how long your script took, what it answered, or whether that changed over the weeks. Yet that is exactly how you spot an import slowly getting out of hand, long before it stops entirely.

And if the hosting itself is not answering, the scheduler goes down with it. It sits on the same machine. A call from outside notices precisely that and sends you an email.

URL to call
https://ihre-domain.de/ihr-skript.php
Recommended interval
every minute
Tested with
IONOS Webhosting
Sufficient Cronjob.de plan
Minute-precise execution and the call log with your server's response start with Cronjob.de Plus, the runtime statistics with Unlimited.

Setup

Step by step

The AI does it faster

You do not have to transfer any of this by hand. Paste this guide – or the one for your own system – into the assistant, and Cronjob.de fills in address, method, schedule and headers. Where something is unclear it asks instead of guessing. At the end you see what was entered and create the job with one click.

Included in the free plan at no extra cost. You will find it after signing in under "Cronjobs" → "Create with AI".

  1. First decide whether the IONOS cron is enough

    For backups, cleanup work and anything running at intervals of five minutes or more, the cronjob management at IONOS is the simpler route. It can start your script directly with PHP or call it by address using curl. Only read on if you need a tighter interval or a log.

  2. Decide on the address and protect it

    For the external call you need an address reachable without a login. Protect it with a long random parameter that your script checks in its first line.

    https://your-domain.com/your-script.php?key=A-LONG-SECRET

  3. Prevent overlap inside the script

    The IONOS advice is justified. If you use a one-minute interval, set a lock in your script: a file created at the start and removed at the end, or an entry in the database. If a copy is already running, the second one aborts immediately. That solves the overlap problem behind the five-minute recommendation.

  4. Create an account at Cronjob.de

    Registration takes a minute and is free. For the one-minute interval you need the Plus plan; the first 14 days run on Unlimited anyway.

    Start for free 14 days of Unlimited included, no payment details

  5. Create a cronjob with that address

    Enter the address and set the schedule, by clicking, as a crontab expression, or by describing the interval in one sentence.

    * * * * *

    You can enter this expression at Cronjob.de exactly as it is – the schedule field understands crontab notation. But you do not have to know it: simply click the schedule together instead.

  6. Switch on error notifications

    Enter an email address under Notifications. You will then also be notified when your hosting is not reachable at all. Failure notifications by email are included from the Plus plan, and free during the first 14 days.

What the five fields of an expression like */5 * * * * mean is explained in the crontab reference – with examples and the most common pitfalls. You can build the expression in the crontab generator. Whether you need an outside service at all is shown in the comparison of the three ways.

Verification

Is it actually running?

In the Cronjob.de call log you see the time, runtime, status code and your script response for every call. If you built in a lock, the runtime should stay even and no call should end in an error.

Your host runs cron jobs itself? Then monitor them with a heartbeat.

One line at the end of your script reports every run to Cronjob.de. If the check-in is missing, you get a message – even if the host's cron never started. One heartbeat is free. Cron job monitoring

FAQ

Common questions about IONOS

Is the IONOS five-minute recommendation a hard limit?
No, IONOS describes it as a recommendation and justifies it with overlapping processes. Anyone who sets a lock in their script no longer has that problem.
Can IONOS call scripts by address too?
Yes. IONOS names curl for that, which simulates a call through the browser and respects your own php.ini settings. The difference from us is not in the call but in the log and the notification.
Should I switch off the IONOS cron?
If you would trigger the same task from both sides, yes. Otherwise two schedules run side by side and you can no longer tell which run came from where.
What happens if my script takes longer than 60 seconds?
We abort the call then. In PHP you can still let the script keep running, with set_time_limit(0) and ignore_user_abort(true) in the first line. Usually it is better to split the work into chunks.
Is your server rejecting our calls? Error 403 almost always comes from a firewall, a security plugin or directory protection – not from your script. All our calls carry the fixed identifier Cronjob.de in the user agent. Ask your host for an exception for it; that is more reliable than allowing IP addresses, because ours can change. Addresses and details in the FAQ. Other errors such as 401, 404 or 500 are explained in the troubleshooting guide.

Create your cronjob now

Create an account, enter the address, click the schedule. Five cronjobs are free forever, the first 14 days run on the Unlimited plan.

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More guides

Official documentation of IONOS

The details about IONOS come from their own documentation, as of September 2026. Please check there whether anything has changed since. IONOS is a trademark of its respective owner. This guide comes from Cronjob.de and has no business relationship with that provider.