Scheduled Scans
Flip one setting per site and Site Health will scan on autopilot. No cron, no servers, no scripts.
How to turn it on
On the site detail page, scroll to Automation and set Schedule frequency:
- Off — no automatic scans (you can still trigger manually or via webhook).
- Daily — fires every day at 09:00 UTC.
- Weekly — fires every Monday at 09:00 UTC.
Changes save instantly. Your next scheduled run appears at the top of the automation card.
What fires
Each scheduled run enqueues a scan using whatever default strategy is saved on the site (Mobile, Desktop, or Both). The scan shows up in the scan history exactly like a manual one — same results, same alerts, same regression detection.
Jitter and thundering herd
If every customer scheduled daily scans at exactly 09:00 UTC, Site Health would blast PageSpeed Insights with hundreds of requests in the same millisecond. To avoid that, the scheduler adds 0-5 seconds of random jitter to every scheduled scan:
fireAt = 09:00:00 UTC + random(0, 5000ms)
You'll see your scan start between 09:00:00 and 09:00:05 — not consequential for your reporting, critical for being a well-behaved API consumer.
Skip rules
The scheduler is idempotent. It will skip a scheduled run if:
- A scan for that site is already queued (waiting for a worker).
- A scan for that site is already running (in progress).
This means a long-running scan won't get a duplicate queued on top of it. The next day's schedule resumes normally.
All schedules run in UTC. If you're in US Pacific, daily 09:00 UTC is 01:00 / 02:00 local (depending on DST). Pick based on when you want the data available, not your local wake-up time.
When to use each frequency
| Setting | Good for |
|---|---|
| Weekly | Stable marketing sites with infrequent publishes. Keeps weekly digest data fresh. |
| Daily | Content-heavy sites, active clients, anywhere you're actively iterating. |
| Off + webhook | Sites that publish irregularly. Pair with Webflow publish webhooks so scans only fire when something actually shipped. |
What's next
- Want emails the moment a scheduled scan breaks something? Set up Alert Rules and Regression Detection.
- Want a summary instead of a blow-by-blow? Turn on the Weekly Digest.