See exactly what your website tracks, and fix what is wrong.
Lumen Strata tests your live website the way a visitor uses it. It goes through your key journeys, such as a form, a sign-up or a checkout, and records what happens at every step: the data layer, every GTM tag, every cookie and every event sent to GA4. Then it shows you what is broken, what was sent before consent, and how to fix it.
Site assessment in progress

Why it matters
A tidy container can still send the wrong data.
GTM shows what should happen. Your live website decides what actually does. A release changes a form, a tag stops firing, a value goes missing, or a marketing tag loads before the visitor has said yes. Nobody notices until the numbers stop adding up.
Numbers you can trust
If a lead or purchase event is missing or carries the wrong value, every report, bid strategy and budget call built on it is wrong too. Strata shows you whether each event reached GA4, and whether its values were right.
Consent you can prove
Strata runs every journey with cookies accepted and again with them denied. You see exactly which tags and cookies respect the visitor's choice and which do not, with the evidence for each.
Retested after every release
Testing journeys by hand in GTM preview mode takes hours and is rarely repeated. Strata records each journey once and replays it whenever you need it, so a change that breaks tracking is caught the same day.
What it checks
What Strata checks at every step of a journey.
Strata connects to GTM and runs every journey in debug mode. That lets it see which tags fire at every step and what data each variable pulls in for every tag, on the live website rather than in theory.
Data layer
- The data layer that fires across the journeys you select
- What is in it today, and what a best practice data layer would look like for your website
- Parameters that are not populating, and gaps in the overall structure
- What changes in the data layer between one step and the next
- Duplicate events, and missing or invalid values
Tracking
- Which tags fired at every step, read from GTM debug mode
- What data each variable captures for every tag
- Whether the data collected is correct for your website
- Whether each tracked event reached GA4, with the right values
How it tests your site
From a list of pages to a test you can repeat.
Discover
Strata explores the site and suggests the user journeys worth testing. You can also name the journeys you want tested, such as a contact form, a sign-up or a checkout.
Record the journeys
Each suggestion becomes a repeatable test. Replay it on demand, for example after a release or a container change.
Check the pages
Strata finds pages from the sitemap and checks a sample of each page type, so a large site is covered without testing every page.
Test consent both ways
Every journey runs twice, once with cookies accepted and once with them denied, so you see exactly what each choice changes.
What you get
Fixes your developers can follow, and a summary your stakeholders can read.
A tracking plan
The events and parameters your site should track, the consent behaviour for each, and a new data layer brief your developers can build from so tracking is clean and correct.
Site assessments
Test many journeys and pages in a single run, and see every result in one place.
A stakeholder report
A plain-language summary of what was found, and of what was not tested.
A Google Sheets export
An executive summary, the top fixes, and a step-by-step spec with screenshots for whoever makes the changes.
The Lumen audit stack
Each Lumen audit covers one layer of your measurement.
Use one on its own, or run them together for the full picture.
GA4 property and GTM container audit. 100+ checks on how your setup is configured.
See Lumen CoreData layer, live tag firing and consent, tested on your live site.
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Request early access to Lumen Strata.
Strata is in early access. Join the waitlist and we will be in touch to set up your first site assessment.
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