Web Development

You're shipping a new product. You need to know how users interact with it. So you grab Google Analytics. It's free. Everyone uses it. Setup is two script tags. Done. Except you run Lighthouse and your site lost 200 points on performance. Your Time to Interactive jumped 400ms. Then you log into the GA4 dashboard and spend 20 minutes finding the conversion report because it's hidden behind five menu layers and named something cryptic like "User Acquisition Events". You wonder: does everyone deal with this, or is there a better way?

Yes, there's a better way. The problem is Google doesn't optimize GA for your site's speed — GA optimizes for Google's servers to collect as much data as possible. PostHog and Plausible exist for the exact opposite reason: they optimize for your site's performance and your privacy obligations. GA4 is free because you are the product. PostHog costs money because you're the customer. Plausible is lightweight because it respects your users' privacy from day one.

Pick the wrong analytics stack and you'll spend six months fighting GA's UI, worrying about GDPR compliance, and watching your Core Web Vitals tank. Pick the right one and you'll have the data you need without the performance penalty. Here's how to decide.

What Is Analytics, Actually?

Analytics is three separate problems wearing a trench coat: (1) traffic metrics (how many users, where they came from, what pages they visited), (2) conversion tracking (did they buy, click the CTA, sign up), and (3) session data (what did they click, where did they rage-quit). GA4 tries to solve all three. PostHog leans into (2) and (3). Plausible handles (1) really well and (2) with lightweight tags. Each is optimized for a different use case.

Most teams use one analytics tool for marketing data (traffic, referral source, blog post performance) and a second tool for product data (funnel drops, user segments, where people churn). GA4 tries to be both. It fails at both because it's designed to maximize data collection for Google, not clarity for you.

GA4: Free But Expensive

Price: $0 → pain

GA4 is free until you hit 1M events/month. At 10M events/month, you're fine. At 100M, Google starts throttling. In practice, GA4 is free forever if your site is small-to-medium. The cost isn't money. The cost is your site's performance and your compliance headaches.

Performance: -200ms TTI

GA4 bundles ~70kb of JavaScript. It parses your DOM, creates event listeners on every button and link, builds a queue of user interactions, and sends batches of data back to Google's servers. All of this runs on your main thread. Wrap it in Partytown (see our Partytown deep-dive) and you cut the impact to -100ms. Still expensive for what you're getting.

Reporting: Byzantine UX

GA4's dashboard is infamous. Conversions are called "Events". Pages are called "Screens". Bounce rate is hidden. Session duration doesn't mean what you think it means. Standard reports exist but you have to build custom ones to answer real questions like "what % of users clicked the CTA?" or "where do people drop out during signup?" Worst part: Google changes the UI every three months and breaks your bookmarks.

Privacy: GDPR Risk

GA4 sends user data to Google's US servers. If you have EU users, GDPR says you need explicit consent to transfer data across borders. GA4 doesn't make this easy. You'll spend hours on cookie banners and consent management before you're fully compliant. Same rules apply in Australia — your Privacy Act requires consent for non-essential tracking.

Setup: Two lines but you'll hate it

<script async src="https://www.googletagmanager.com/gtag/js?id=G-XXXXX"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config', 'G-XXXXX');
</script>

Two lines gets you tracking page views. Custom events? You're custom-coding every CTA in your product. GA4 expects you to learn their event schema and push data manually. It's flexible. It's also tedious.

PostHog: Product Analytics + Session Replay

Price: Freemium, then $450+/month

PostHog's free tier includes 1M events/month + 5K session recordings. Enough for a startup. Paid plans start at $450/month for small teams. You're paying for product analytics (funnels, cohorts, feature flags) and session replay (watch users interact with your site in real-time). It's expensive but teams love it because the data is so clear.

Performance: -50ms TTI (lighter than GA4)

PostHog's library is ~20kb gzipped. Lighter than GA4. It captures events client-side and batches them. Session replay is opt-in. If you enable replay, expect an extra 30-50kb load. Wrap both in Partytown and you're down to -10ms impact. Negligible for most sites.

Reporting: Crystal Clear

PostHog is built for product teams. Funnels are visual: drag steps onto a canvas, see drop-off rates. Cohorts let you segment users (e.g., "users who clicked CTA but didn't convert"). Session replay shows you exactly what a user did before they rage-quit. You can save custom dashboards. The UX never changes. This is what GA4 wishes it was.

Privacy: Self-Hosted or GDPR-Ready

PostHog has two deployment options: (1) Cloud (they handle the infra, you send data to PostHog servers), (2) Self-hosted (you run PostHog on your own server, data stays in your infra). For EU users, self-hosting makes GDPR trivial — data never leaves your country. Australia's Privacy Act is less strict than GDPR, but self-hosting still gives you peace of mind. Cloud option is in EU data centers if you need it.

Setup: One line + custom events

<script>
  !function(){var analytics=window.posthog=window.posthog||[];
  if(analytics.invoked)return;analytics.invoked=!0;
  var e=document.createElement("script");e.async=!0,e.src="https://cdn.posthog.com/array.js";
  document.head.appendChild(e);
  }();
  posthog.init('phc_YOUR_API_KEY', {api_host: 'https://app.posthog.com'});
</script>

Copy-paste the script. Then instrument your app with custom events: `posthog.capture('cta_clicked')`. That's it. PostHog auto-tracks page views, clicks, and form submissions. You add business logic on top. Clean and intentional.

Plausible: Lightweight, Privacy-First

Price: €9-20/month (fixed pricing)

Plausible charges a flat fee based on your page views. 10K page views/month = €9. 1M page views/month = €20. No hidden tiers. No per-event pricing. No consent management upsell. You know your cost upfront. For marketing sites, it's the cheapest option after GA4.

Performance: +1.5kb (nearly free)

Plausible's script is 1.5kb gzipped. One percent the size of GA4. No event listeners. No DOM parsing. It just counts page views and lets you tag custom events. Load time is imperceptible. This is the fastest analytics library in existence.

Reporting: Simple and Focused

Plausible doesn't do session replay or cohorts. It does one thing well: show you traffic metrics cleanly. Page views, top pages, referral sources, device breakdown, geographic split. You see a chart and instantly understand what's happening. No custom reports needed. No hidden menus. It's refreshingly straightforward.

Privacy: GDPR + Australia Privacy Act Compliant by Default

Plausible doesn't use cookies. No consent banner needed. It hashes user IP to generate a unique session without storing PII. Fully compliant with GDPR, ePrivacy Directive, and Australia's Privacy Act out of the box. Your users' data stays yours. Plausible just aggregates metrics.

Setup: One line, that's it

<script defer data-domain="yoursite.com" src="https://plausible.io/js/script.js"></script>

Paste it in your Layout component. Page views are tracked automatically. Custom events are one line: `plausible('event_name')`. No API keys, no config, no ceremony. Start getting data immediately.

Side-by-Side Comparison

When to Use Which

Use Plausible if:

You're building a marketing site, landing page, or blog. You need to know traffic sources, top pages, and basic conversion events. You care about privacy and Core Web Vitals. You want setup that takes 30 seconds and never requires maintenance. Plausible is the easiest choice for this use case.

Use PostHog if:

You're shipping a product and need to understand user behavior deeply. You need session replay to watch where users get stuck. You need funnels and cohorts to segment users and find growth leaks. Your team is technical and wants a single source of truth for product analytics. PostHog is worth the cost if you're iterating on product-market fit.

Use GA4 if:

Your marketing team demands it. Your sales org needs GA's integrations (Sheets, Data Studio, BigQuery). You're comfortable with performance tradeoffs and GDPR complexity. For most teams, this is the wrong default. But if your stakeholders insist, wrap it in Partytown and accept the UX tax.

Stack Both (Realistic):

Velocity X runs Plausible on marketing sites + PostHog on products. Plausible tells you traffic. PostHog tells you conversion. GA4 is optional if your marketing team needs it for reporting to leadership. Run all three if budget allows — they each solve a different problem and the overhead is tiny if you Partytown-wrap them.

Setup Patterns for AU + GDPR Privacy

Australia Privacy Act (less strict than GDPR):

You need consent for non-essential tracking (like advertising pixels). Essential analytics (page view counts, basic traffic source) don't require consent. In practice: use Plausible without a consent banner. If you add Meta Pixel or Google Ads conversion tracking, add a cookie banner then.

GDPR (EU users — stricter):

All tracking requires explicit opt-in consent. Cookie banners are mandatory. The strategy: (1) build a simple cookie banner that asks for "Analytics" consent, (2) don't load Plausible / PostHog until the user consents, (3) store their choice in localStorage. Most consent managers (OneTrust, Cookiebot, Termly) integrate with analytics libraries. If you self-host PostHog in an EU data center, GDPR becomes "user consents to analytics, data stays in the EU, done".

Practical implementation (both regions):

// Only load Plausible if user consents (or if no consent choice made after 30 days)
if (localStorage.getItem('analytics_consent') !== 'false') {
  const script = document.createElement('script');
  script.defer = true;
  script.dataset.domain = 'yoursite.com';
  script.src = 'https://plausible.io/js/script.js';
  document.head.appendChild(script);
}

Simplest approach: Plausible by default (no cookies, Privacy Act compliant). If you have EU traffic, add a one-sentence banner asking for consent. Done. No third-party consent manager needed.

Six FAQs

Can I run all three simultaneously?

Yes, but why? Plausible + PostHog is a sensible combo (marketing + product metrics). Adding GA4 adds 70kb bloat and reporting confusion for no gain. If your org mandates GA4, use it — but don't expect clarity.

Does Plausible's hashed IP method actually protect privacy?

It's better than cookies, not perfect. Plausible hashes the user's IP + user-agent once per 24 hours to generate a session ID. Combined with not storing PII, it's compliant with GDPR and Australia's Privacy Act. You can disable even this hashing if you want (analytics becomes fully aggregate, no session tracking).

Can I export data from PostHog / Plausible?

PostHog: yes, API access and custom exports. Plausible: yes, CSV export of basic reports. Neither is as open as GA4's BigQuery integration, but both let you get your data out.

What if I'm using GTM (Google Tag Manager)?

GTM is a script that loads other scripts. It's heavier than any single analytics library but lets you manage multiple tags from one dashboard. If you use GTM to load GA4, Plausible, and Meta Pixel, wrap the whole GTM script in Partytown. GTM will offload all its tags to a web worker. Same privacy rules apply — each tag still needs consent if required by GDPR/Privacy Act.

Do I need both PostHog and a CRM like Pipedrive?

They solve different problems. PostHog shows you how users interact with your site. Pipedrive tracks deals and relationships. If you're B2B, you probably need both. PostHog tells you "signup funnels drop 30% at pricing page." Pipedrive tells you "which deals are likely to close." Use both, sync PostHog events to Pipedrive via webhooks.

Switching analytics libraries — will I lose historical data?

Yes, unless you export first. When you switch from GA4 to Plausible, GA4's data stays in GA4. Plausible starts fresh. If historical data matters (e.g., you need 6-month trend reports), export GA4's data to BigQuery, then build custom dashboards. For most teams, "start fresh with better analytics" is worth the tradeoff.

The Bottom Line

GA4 is a trap. It's free, which is why everyone uses it, but you pay the cost in performance, privacy complexity, and your team's sanity trying to use the reporting UI. If you must use it, wrap it in Partytown and accept the pain.

PostHog is for product teams who need deep behavioral data and can afford $450+/month. The session replay and funnel analysis pay for themselves in faster iteration.

Plausible is for everyone else. It's 1.5kb, privacy-first, costs €9-20/month, and requires zero compliance anxiety. It doesn't do session replay, but for marketing sites and blogs, you don't need it. Start with Plausible. Layer PostHog if you later need product analytics. Skip GA4.

Built a product with analytics that's slowing your site down? Check out Aidxn Design's web performance consulting to audit your tracking overhead, or dive deeper into third-party performance with our Partytown guide.