All guides
How-to guideVolume monitor

Set up a volume monitor

A volume monitor tracks how many times your dataLayer events fire each day. When the count drops significantly below the historical baseline, TagWatch sends an alert so you know something broke before your team notices missing conversions. The easiest way to set one up is via the Incoming Events tab: once your GTM tag is firing, events appear automatically and you create a monitor in one click.

2 minutes·No technical knowledge required
1

Make sure your GTM tag is sending events to TagWatch

If you did not install the TagWatch GTM tag yet, follow the Import the TagWatch GTM template guide first. Once the tag is live and firing, events will start appearing automatically with no extra setup needed.

2

Open Monitors → Incoming Events

From the sidebar, click Monitors, then switch to the Incoming Events tab. Every event TagWatch has received from your domains is listed here, including the domain it came from, how many times it has been seen, and when it last fired. A pulsing dot on the tab tells you events arrived that have no monitor yet.

EventDomainSince tracking
purchaseyourshop.com1.2k since 18 Apr
Add monitor
add_to_cartyourshop.com8.4k since 18 Apr
Monitored →
3

Click 'Add monitor' next to the event you want to watch

Hit Add monitor on any event row. TagWatch creates the monitor instantly with the name, domain, and event name all filled in automatically. No wizard, no configuration needed.

The monitor appears immediately in the Monitors tab and the row turns orange with a Monitored → badge. You can open the monitor to adjust the name or alert threshold at any time.

Event not there yet?

Events only appear after the first real browser visit that fires the tag. Open your site in a new tab, complete the action (e.g. add something to cart), then refresh the Incoming Events tab. It can take up to 30 seconds to show up.

4

Done. TagWatch starts building a baseline

TagWatch checks your event volumes every morning, when yesterday is complete, and again in the afternoon as an early warning on today. The monitor shows a Provisional baseline badge at first. Flatlines are caught as soon as there is history; percentage drop alerts start once four weeks of same weekday data exist and the event averages at least 10 a day. One Baseline ready email tells you when your critical events reach a normal baseline.

The Add Monitor wizard walks you through installing the tag, with the GTM template handed to you and your Tenant ID already filled in. The monitors themselves are created here, from Incoming Events.

Once running, the monitor shows the baseline status and recent event history:

Purchase event monitor
Event TrackingNormal baselinepurchaseadd_to_cart
Threshold: 80% drop · checked morning and afternoon
purchase1,240 yesterdaybaseline ~1,380/day
add_to_cart4,820 yesterdaybaseline ~4,600/day

Tips for reliable volume monitoring

  • Use the Incoming Events tab for one-click setup

    Once your GTM tag is firing, open Monitors, switch to Incoming Events, and hit Add monitor. The name and domain are filled in automatically.

  • Start with your most critical conversion event

    Add purchase or generate_lead first. These are the events where a drop hurts most and where you want the fastest alert.

  • Do not monitor events that fire only occasionally

    Sporadic events have no meaningful daily baseline, and percentage alerts stay paused below an average of 10 a day. Volume monitors work best for events that fire at least 10 to 20 times a day.

  • Tune the threshold after a few weeks

    The default 80% threshold catches real breakage and ignores ordinary bad days. Once you have baseline data you can tighten it in the monitor settings for events whose counts barely move.

Ready to set up your first monitor?

Start your 14-day free trial. No credit card required.

Start free trial →