Migrate from GA4. Without the rip-and-replace.
GA4 is not a tool you migrate off — it is a tool you migrate past. This is the 30-day parallel-run plan most EU eCommerce teams use to move strategic decisions off GA4 while keeping the Google Ads conduit intact.
Why teams are migrating in 2026
GA4 works. For Google Ads integration, for search-keyword joining, for the entry-level reporting most sites do not outgrow. The teams migrating are the ones that have outgrown those use cases — and one of three patterns usually applies.
Pattern 1 — The CFO stopped accepting the reconciliation gap
Marketing reports €X. The CRM reports €Y. Finance reports €Z. The 25–40% gap eats hours of every quarterly review and decisions wait another week. Eventually someone above marketing says “fix the measurement first” — and the search for complete data begins.
Pattern 2 — The DPO asked questions GA4 cannot answer
A DPIA refresh, an authority audit, a Digital Omnibus briefing — and suddenly the cookie banner, the US data transfer and the Consent Mode v2 modelling all need defending in writing. GA4’s compliance defence is always “here are the layers we added on top.” Cookieless EU-hosted is the answer for teams that prefer lawful by architecture over lawful by paperwork. See the consentless analytics pillar for the framework.
Pattern 3 — The AI stack arrived and GA4 had no plug
Marketing wants to query channel performance through ChatGPT, Claude or an internal agent. GA4’s Looker-Studio path is brittle for agents; the BigQuery export is sampled above thresholds. SealMetrics ships a native MCP server, full-resolution BigQuery, and answers that an agent can quote without a wrapper.
The approach: parallel-run, not cutover
Every migration plan that says “rip out GA4 and install the replacement” is selling, not advising. The plan that works is the one that runs both tools side by side until the team trusts the new numbers more than the old ones. Three reasons:
- Side-by-side comparison is the only honest way to measure your real data gap against your own CRM.
- Google Ads conversion import lives in GA4. Removing GA4 day one breaks bidding signals on Google Ads.
- Stakeholders trust dashboards they have used for years. Trust transfers when the new numbers reconcile with the CRM and the old ones do not — visible, weekly, in writing.
The 30-day parallel-run checklist
One day of setup, four weeks of comparison, one meeting at day 30 to decide what stays where.
- Day 0
Install alongside GA4
Add the 846-byte first-party SealMetrics pixel via the same tag manager you already use for GA4. Configure the CNAME under your own domain (e.g. pixel.yourdomain.com). Verify event firing in the SealMetrics debugger.
- Day 1
Map the conversion events
Mirror the conversion events you track in GA4 (purchase, lead form, signup) into SealMetrics. For Shopify, WooCommerce, Magento and PrestaShop the order events flow automatically through native integrations.
- Week 1
Pull the first reconciliation report
Compare SealMetrics aggregate conversions against the CRM or backend (Shopify orders, WooCommerce orders, your order DB). Compare against GA4 in the same report. Document the gap by channel — direct, organic, paid search, paid social, email.
- Week 2
Run the first weekly review with marketing
Two columns: GA4 numbers and SealMetrics numbers. Same week. Same channels. Walk through which channels gain share, which lose share, which lose attribution to 'direct' under GA4. The pattern is consistent across customers; the magnitude is yours.
- Week 3
Bring in the agencies
Share the comparison with paid-media agencies. Ask them to interpret the gap. The good ones will engage with the SealMetrics numbers; the ones that resist usually do so because their reporting depends on the GA4 view of their performance.
- Day 30
Decide what stays where
One meeting, one decision. Most teams settle on: GA4 stays for Google Ads conversion import and Search Console join. SealMetrics becomes the source of truth for revenue, channel mix, paid ROAS, board reporting. Update the dashboards stakeholders see; close the GA4-only views.
What you keep, what you replace
Keep GA4 for
- Google Ads conversion import (the bidding signal).
- Search Console keyword joining (organic search query data).
- Looker Studio dashboards that already depend on the GA4 dataset.
- Historical comparisons (year-over-year against pre-migration GA4 data).
Replace with SealMetrics
- Revenue and conversion reporting (the number you decide on).
- Channel mix and paid ROAS for board-level reporting.
- Reconciliation against CRM / Shopify / PMS — the source of truth.
- EU compliance posture — GDPR / ePrivacy by architecture, EU-only processing.
- AI-agent and MCP integration for the rest of the analytics stack.
For the feature-by-feature comparison, see SealMetrics vs Google Analytics 4. For the architecture of how 100% capture is possible, see cookieless analytics.
Common migration questions
- Do I have to remove GA4?
- No. Most teams keep GA4 running indefinitely. GA4 is the conduit Google requires for Google Ads conversion import and the easiest path to Search Console / Looker Studio joins. What changes is what you decide on. After 30 days of parallel running, most customers shift revenue and channel-mix decisions to SealMetrics and let GA4 handle the Google-Ads side. Two tools, two purposes.
- How long does the migration actually take?
- Five minutes to install. First data in the first hour. Decision-ready in week one. Full calibration to your CRM within 30 days of parallel running. There is no historical-data migration step — SealMetrics begins counting from day one on new data; GA4's historical data stays in GA4 for reference.
- What about my BigQuery export from GA4?
- Keep it for historical reference. SealMetrics ships native BigQuery export at full resolution (no sampling thresholds) from the Growth plan up. Most teams add the SealMetrics dataset alongside the GA4 dataset and join them in the warehouse — the GA4 dataset for pre-migration history, the SealMetrics dataset as the source of truth going forward.
- How does the EU consent banner change?
- If SealMetrics replaces the analytics layer entirely, the analytics-specific reason for the banner disappears. The banner may still be required for other tools — Meta pixel, Google Ads remarketing, A/B testing platforms that set cookies. Many teams reduce the banner scope (or remove it on pages without ad pixels) once analytics moves to a cookieless layer. The full legal walk-through lives on the consentless analytics pillar.
- Will my paid agency push back?
- Some will. The honest framing: agencies optimise toward the numbers the platform reports. When those numbers are an estimated 13% of EU reality, optimisation rewards channels that consent more, not channels that perform better. Once you and your agency see the SealMetrics numbers alongside the CRM, the conversation moves from defending the GA4 dashboard to which channels actually drove the orders. Most agencies adapt; the ones that don't were defending the tool, not the result.
- Can we migrate gradually or do we cut over?
- Gradually, always. SealMetrics is designed to run alongside GA4 from day one — same script tag pattern, parallel ingest, side-by-side dashboards. After 30 days of comparison, decide per use case where each tool fits. Most teams never fully decommission GA4 because the Google Ads integration is valuable; they just stop making strategic decisions on it.
How Palladium Hotel Group ran the 30-day parallel.
“The data SealMetrics delivers is agnostic, unbiased and neutral. There’s no black box.”
Toni Andújar · Digital & Direct Sales Director · Palladium Hotel Group
Palladium ran SealMetrics alongside their existing GA-tier stack for the first month. The audit surfaced 40% of inbound traffic with no source/medium attribution in GA, 35% of bookings unassigned to a channel, and a +165% Cost-per-Search improvement on Display once the SealMetrics measurement model drove DV360 decisions. They kept GA as the Google Ads conduit and moved revenue decisions to SealMetrics.
Read the full Palladium case study →Run the parallel month. Decide at day 30.
Book a 30-minute walkthrough with the founder. We map your GA4 events to SealMetrics live and ship the parallel-run plan tailored to your stack.
Built by a founder · supported by a founder · EU-hosted by design