Optimize PostHog costs through tier selection, sampling, and usage monitoring.
Use when analyzing PostHog billing, reducing API costs,
or implementing usage monitoring and budget alerts.
Trigger with phrases like "posthog cost", "posthog billing",
"reduce posthog costs", "posthog pricing", "posthog expensive", "posthog budget".
PostHog Cloud pricing is event-based: 1M events/month free, then usage-based pricing beyond that. Session recordings, feature flag evaluations, and surveys each have their own free tiers. The biggest cost drivers are typically $autocapture events, $pageview on high-traffic pages, and bot traffic. This skill covers specific techniques to reduce event volume without losing analytical value.
Prerequisites
PostHog Cloud account with billing access
Application instrumented with posthog-js
Understanding of which events drive your analytics
PostHog Cloud Free Tiers (2025)
Product
Free Tier
Overage
Product analytics
1M events/month
~$0.00031/event
Session recordings
5K sessions/month
~$0.04/session
Feature flags
1M API requests/month
~$0.0001/request
Surveys
250 responses/month
~$0.10/response
Instructions
Step 1: Audit Current Event Volume
set -euo pipefail
# See which events consume the most quota (last 30 days)
curl "https://app.posthog.com/api/projects/$POSTHOG_PROJECT_ID/query/" \
-H "Authorization: Bearer $POSTHOG_PERSONAL_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"query": {
"kind": "HogQLQuery",
"query": "SELECT event, count() AS total FROM events WHERE timestamp > now() - interval 30 day GROUP BY event ORDER BY total DESC LIMIT 20"
}
}' | jq '.results[] | {event: .[0], count: .[1]}'
Step 2: Tune Autocapture
$autocapture is often the largest event volume. Restrict it to only useful interactions.
import posthog from 'posthog-js';
posthog.init(process.env.NEXT_PUBLIC_POSTHOG_KEY!, {
api_host: 'https://us.i.posthog.com',
autocapture: {
// Only capture click and submit events (skip change, scroll, etc.)
dom_event_allowlist: ['click', 'submit'],
// Only capture meaningful elements
element_allowlist: ['a', 'button', 'form', 'input[type=submit]'],
// Only capture elements with this CSS class
css_selector_allowlist: ['.track-click', '[data-track]'],
// Skip internal/admin pages entirely
url_ignorelist: ['/admin', '/health', '/api/internal', '/_next'],
},
});
Step 3: Event Sampling with before_send
posthog.init(process.env.NEXT_PUBLIC_POSTHOG_KEY!, {
api_host: 'https://us.i.posthog.com',
before_send: (event) => {
// 1. Always send business-critical events (no sampling)
const critical = ['purchase', 'signup', 'subscription_started', 'subscription_canceled', 'error'];
if (critical.includes(event.event)) return event;
// 2. Drop bot traffic entirely
const ua = navigator?.userAgent?.toLowerCase() || '';
if (/bot|crawler|spider|scrapy|headless|phantom|puppeteer/i.test(ua)) {
return null;
}
// 3. Sample pageviews to 25% on high-traffic pages
if (event.event === '$pageview') {
const highTraffic = ['/', '/pricing', '/blog'];
const url = event.properties?.$current_url || '';
if (highTraffic.some(p => url.endsWith(p))) {
return Math.random() < 0.25 ? event : null;
}
return event; // Keep other pageviews at 100%
}
// 4. Sample autocapture to 20%
if (event.event === '$autocapture') {
return Math.random() < 0.2 ? event : null;
}
// 5. Sample pageleave to 50%
if (event.event === '$pageleave') {
return Math.random() < 0.5 ? event : null;
}
return event; // Keep all other events
},
});
Step 4: Optimize Session Recording Costs
posthog.init(process.env.NEXT_PUBLIC_POSTHOG_KEY!, {
api_host: 'https://us.i.posthog.com',
session_recording: {
// Record only 10% of sessions (saves 90% on recording costs)
sampleRate: 0.1,
// Don't record sessions shorter than 5 seconds (bounces)
minimumDurationMilliseconds: 5000,
// Record 100% of sessions with errors (most valuable for debugging)
// This is configured in PostHog dashboard under Session Replay settings
},
});
// Alternatively: disable recording for non-paying users
posthog.init(process.env.NEXT_PUBLIC_POSTHOG_KEY!, {
api_host: 'https://us.i.posthog.com',
disable_session_recording: true, // Start disabled
});
// Enable only for paying users
if (user.plan !== 'free') {
posthog.startSessionRecording();
}
