Web analytics tools, compared on what separates them

Most teams arrive here because GA4 is not answering the question they have. Before comparing feature lists, it is worth being clear about the three things that limit a web analytics tool: whether it samples your data, how long it keeps it, and whether it can tell that two visits were the same person.

What separates a good one from a bad one

Sampling and thresholding
GA4 samples large queries and hides rows when volume is low. If a number can quietly change or disappear, it cannot be the number you report.
Data retention
GA4 defaults to two months and caps at fourteen. Any year-over-year question is gone before you ask it.
Identity across devices
A session model cannot join a phone visit to a desktop purchase. That gap shows up as unattributed revenue.
Privacy and hosting
Where data lives, and whether the tool can be run without consent banners, has become a procurement question in the EU rather than a preference.

How to decide

Sort the tools by what they refuse to do. Lightweight privacy tools refuse identity, so they can be simple and consentless. GA4 refuses retention and unsampled queries at the free tier, so it can be free. Person-level tools refuse neither, so they cost money and hold more data. Decide which refusal you can live with; that answers the category faster than any feature grid.

The last column says when each tool, including ours, is the right choice. Where a full head-to-head exists, the name links to it.

  • Kissmetrics

    Person-level analytics · Free, then $99/mo

    The question is who became a customer, what they are worth, and which channel brought them.

  • Google Analytics 4

    Web Analytics · Free

    You need free traffic reporting at any volume and your spend runs through Google Ads.

  • Matomo

    Web Analytics (Open Source) · Free (self-hosted)

    You want full ownership on your own servers and are willing to operate it.

  • Plausible Analytics

    Privacy-First Web Analytics · $9/mo

    You want a fast, consent-light pageview counter and nothing more, at the lowest cost.

  • Adobe Analytics

    Enterprise Web Analytics · Custom pricing

    You are an enterprise with an Adobe stack and a team dedicated to running it.

  • Mixpanel

    Product Analytics · Free (up to 1M events/month)

    The website is really a product, and in-product behavior matters more than traffic.

  • Heap

    Product Analytics · Free (limited)

    You want every click captured retroactively and will define events after the fact.

ToolCategoryStarting priceChoose it when
KissmetricsPerson-level analyticsFree, then $99/moThe question is who became a customer, what they are worth, and which channel brought them.
Google Analytics 4Web AnalyticsFreeYou need free traffic reporting at any volume and your spend runs through Google Ads.
MatomoWeb Analytics (Open Source)Free (self-hosted)You want full ownership on your own servers and are willing to operate it.
Plausible AnalyticsPrivacy-First Web Analytics$9/moYou want a fast, consent-light pageview counter and nothing more, at the lowest cost.
Adobe AnalyticsEnterprise Web AnalyticsCustom pricingYou are an enterprise with an Adobe stack and a team dedicated to running it.
MixpanelProduct AnalyticsFree (up to 1M events/month)The website is really a product, and in-product behavior matters more than traffic.
HeapProduct AnalyticsFree (limited)You want every click captured retroactively and will define events after the fact.

Where Kissmetrics fits

Kissmetrics is not a lightweight GA4 replacement and does not try to be. There is no sampling, no thresholding and no retention cap, and every event resolves to a person. If you want a simple privacy-first pageview counter, Plausible or Matomo will serve you better and cost less.

Try it on your own data before you shortlist anything

100,000 events a month, free, no card. Funnels, Activity, metrics and dashboards come ready-made, so you can try it on your own data while you compare.

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Questions

What is the best free web analytics tool?
It depends what free needs to cover. Plausible and Matomo are open source and can be self-hosted at no license cost. GA4 is free at very high volume but samples and thresholds. Kissmetrics is free to 100,000 events a month with Funnels, Activity, Live view, the chat, metrics, dashboards and the API; Growth adds the campaign report, visitors from AI assistants, Populations and the other reports.
Is Google Analytics still worth using in 2026?
For traffic reporting and Google Ads integration, yes, and it is free. The limits are structural rather than fixable: sessions as the unit, sampling on large queries, thresholding on small ones, and a two-month default retention. Most teams keep it and add something person-based for revenue questions.
Which web analytics tools are GDPR compliant?
Compliance depends on your configuration and legal basis, not only on the vendor. Self-hosted Matomo and Plausible keep data on infrastructure you control, which shortens the assessment. Any US-hosted tool moving EU data will rely on Standard Contractual Clauses, which is lawful but is a question your counsel should answer rather than a badge.

Comparing two specific tools? Every head-to-head comparison.

Kissmetrics

Try it on your own data for free.

Free to start, no card. Install with AI in about 5 minutes.