It is not uncommon to see differing sessions counts when comparing session data across the Polar Pixel and a different source. This guide provides comprehensive details on what could cause differing sessions counts in general.
If you're specifically noticing that the Polar Pixel is reporting fewer sessions than another tool (for example, GA4, Shopify, TripleWhale, Mixpanel, Northbeam, etc), the short answer is that these tools each measure “sessions” very differently, because they use distinct tracking models, cookie rules, and event lifecycles.
Here’s a clear summary of the main differences and why your Polar Pixel sessions might appear lower than another tracking model:
1. Different Tracking Models
Polar Pixel uses first-party, server-side tracking, which means it records events tied directly to verified Shopify orders and visitor interactions on your domain. It doesn’t double-count visits or rely on third-party cookies that browsers often block .
GA4, by contrast, uses client-side, cookie-based tracking that often inflates sessions due to ad blockers, cross-domain issues, and device fragmentation. For example, if a single user visits from mobile and then desktop, GA4 often counts two sessions — whereas Polar Pixel recognizes it as one unified journey.
Mixpanel specifically is event-based, meaning it focuses on tracking specific in-app or on-site actions, and will often log more sessions or events because of its looser event definitions.
2. Session Definition
GA4 restarts a session after 30 minutes of inactivity, or when campaign parameters (UTMs) change — even if it’s the same user returning moments later.
Polar Pixel doesn’t use session breaks in this way; it defines a user journey based on first-party identifiers and Shopify data continuity, so it’s more conservative and accurate but yields fewer counted sessions.
3. Identity Resolution and Blocking
Polar Pixel leverages first-party domain proxying and server-side forwarding, which makes it resilient to privacy blockers — but not all traffic can be matched if the browser prevents identity resolution.
GA4 and Mixpanel rely on cookies, so they may still count visits without a valid ID (hence higher sessions but lower quality tracking).
In essence, Polar’s model filters out noise, giving a cleaner dataset rather than inflated visits.
4. Attribution Logic
Polar focuses on deduplicating conversions and cross-session attribution, meaning it doesn’t create new sessions for every UTM change or referral.
GA4 frequently resets attribution per session — this inflates traffic but fragments the customer journey.
5. Expected Pattern
If GA4 shows 20,000 sessions and Polar shows 12,000–14,000 for the same period, that’s typically normal. Polar’s session numbers are lower but truer, reflecting verified, identifiable customer interactions — not every browser ping or half-session lost to ad blockers.
Key Takeaways:
Polar Pixel = truth-based tracking (server-side, first-party, deduplicated). Polar is designed to provide unbiased, end-to-end visibility across customer journeys while avoiding artificial inflation of traffic metrics seen in cookie-based systems .
GA4 = behavior-based tracking (client-side, cookie-based, inflated)
Mixpanel = event-based tracking (less about sessions, more about activity volume)
For more details, you can read our additional Help Center guides here: