Sealmetrics vs Google Analytics 4
Sealmetrics and Google Analytics 4 are both web analytics tools that report traffic, sources, conversions and revenue. The main difference is the identifier: GA4 relies on a first-party cookie and therefore on visitor consent in the EU, while Sealmetrics sets no cookie, stores no IP address and, in our self-assessment, needs no banner for its own analytics. In practice that means GA4 reports the visitors who accepted the banner, and Sealmetrics reports all of them.
Side-by-side
Google facts checked 2026-09-04 on Google's own help pages; each row links to the page it was read on.
| Criterion | Sealmetrics | Google Analytics 4 |
|---|---|---|
| Company / HQ | Sealmetrics, EU company | Google LLC, Mountain View, USA; Google Ireland Limited for EEA users (source) |
| Hosting model | Managed cloud only | Managed cloud only (source) |
| Identifier between pageviews | Device-characteristics hash computed in the browser, not derived from IP, never written to the device (no cookies or localStorage); re-keyed server-side with a daily salt; live session ~2 h (details) | First-party cookie _ga with a 2-year default expiry, used "to distinguish users" (source) |
| Visitor IP address | Never stored; country derived from browser timezone (details) | Not logged or stored for EU/UK/CH users; used for geolocation and then discarded (source) |
| Data residency | Dublin, Ireland only (details) | EU device data collected on EU servers "before forwarding traffic to Analytics servers for processing"; final location not stated (source) |
| Vendor's position on consent | No banner needed for its own measurement (self-assessed; Germany: open question) | Consent required for cookies "where legally required" under Google's EU User Consent Policy (source) |
| Behaviour when consent is denied | Not applicable — measurement does not depend on consent | Tags send cookieless pings; gaps filled by conversion and behavioural modelling (source) |
| Script size (gzipped) | 1.1 KB (measured) | Not published; Sealmetrics measured ~145 KB on 27 Aug 2026 (method) |
| Free tier | Free tier of 1M events total (lifetime, not monthly), no credit card; 14-day free trial of paid plans (billing) | Standard properties free; Analytics 360 paid with SLA (source) |
| Data retention | 24 months, fixed for every plan | 2 or 14 months for event data; up to 50 months on 360 (source) |
How each one measures visitors
GA4 writes a client ID into the _ga cookie on the first pageview and reads it back on every later one. That single mechanism is what makes unique visitors, session duration, cross-session journeys and audience lists possible — and it is also what puts GA4 inside the scope of the ePrivacy Directive's consent requirement. Google's own policy requires legally valid consent for cookies where the law demands it, and when a visitor declines, GA4 falls back to cookieless pings and statistical modelling rather than measurement.
The Sealmetrics tracker sends only what's needed to measure the visit — current URL, referral URL, timestamp and browser timezone — plus a session identifier: a hash of standard device characteristics computed in the browser, never written to the device, and re-keyed on the server with a daily salt so it cannot link a device across days. A session ends after roughly two hours of inactivity. The user agent is read in flight for bot and device detection (only the derived browser, OS and device category is stored). Nothing is stored on the visitor's browser, the IP is checked in flight against a public list of automated-traffic IPs to filter bots and is not kept, and the country comes from the browser's timezone. Because nothing is stored on the device and the session identifier rotates daily and cannot be reconstructed afterwards — not even by Sealmetrics — Sealmetrics self-assesses that it fits the ePrivacy audience-measurement exemption, so no banner is shown. Germany is an open question: the DSK does not extend §25(2) TDDDG to audience measurement, and the tracker reads device properties via JavaScript, which may count as "access" under §25(1) — see Germany. The cost of that design is fixed: no unique visitors, no session duration, no exit pages, no user journeys.
When Google Analytics 4 is the better choice
- You optimise Google Ads with audience sync and automated bidding — Sealmetrics attributes campaigns via UTMs but does not push audiences back to Google Ads.
- You need user-level analysis: cohorts, cross-device journeys, predictive metrics, or a BigQuery pipeline you have already built on GA4's event schema.
- Most of your traffic comes from markets where consent rejection is low, so the data gap that motivates a switch is small.
When Sealmetrics is the better choice
- Your EU traffic is material and you are losing part of it to the banner — how much depends on sector, brand strength and traffic mix, so measure it side by side.
- Your DPO wants a short answer to "what personal data does the analytics tool process?" — the answer here is a pseudonymised session identifier that rotates daily and becomes unrecoverable, a per-hit log purged after one day, and aggregated reports, with a DPA ready to sign.
- Page weight matters: the tracker fits in a single TCP packet and fires before a visitor can abandon the page.
Frequently asked questions
Can I run GA4 and Sealmetrics at the same time?
Yes, and many teams do during a transition. The two scripts do not interfere, and running them side by side is the easiest way to see the size of the consent gap on your own traffic. The GA4 migration checklist describes the parallel-run period.
Does GA4 store IP addresses?
Google states that it does not log or store individual IP addresses from EU, UK or Swiss users, and that IP data is used for geolocation and then discarded. Sealmetrics goes one step further: the IP is never used for geolocation at all — country comes from the browser timezone.
Why does GA4 show more Direct traffic than Sealmetrics?
When a visitor arrives from a campaign and declines the banner, GA4 cannot set its attribution cookie, so the visit is filed as Direct. Sealmetrics reads UTM parameters on arrival without any cookie, so attribution does not depend on the banner outcome.
Is Sealmetrics less detailed than GA4?
For anything that requires following an individual — unique visitors, session duration, journeys — yes, by design. For aggregate traffic, conversions, revenue and attribution, GA4 covers the consenting subset, while Sealmetrics also measures the traffic GA4 loses to the cookie banner.
- GA4's identifier is a 2-year cookie, so EU measurement depends on the banner; Sealmetrics uses no cookie and needs no banner for its own analytics (self-assessed; Germany: open question).
- GA4 discards EU IPs after geolocation; Sealmetrics never uses the IP for geolocation and hosts and processes analytics data only in the EU (Dublin).
- GA4 offers user-level analysis and Google Ads audience sync; Sealmetrics trades those for consent-independent data.