Server-Side Pixel Forwarding · VSLStats Knowledge Base

Ad blockers, Safari's Intelligent Tracking Prevention, and Apple's iOS 14+ App Tracking Transparency framework collectively block a significant share of browser-side pixel events. Server-side forwarding sends events directly from VSLStats' servers to ad platforms, bypassing these restrictions and dramatically improving data accuracy.

Why Server-Side Beats Client-Side

Traditional browser pixels fire JavaScript in the visitor's browser. This creates several failure points:

Ad blockers - uBlock Origin, Brave, and browser extensions block pixel domains by default. Depending on your audience, this can affect 20–40% of traffic.
iOS 14+ ATT - Apple requires explicit opt-in for tracking. Visitors who decline prevent the Meta Pixel from firing at all on Safari and iOS apps.
Cookie restrictions - Third-party cookies are being phased out, limiting attribution windows for browser-based pixels.
Page load speed - Every pixel script adds page weight and introduces potential render-blocking.

Server-side forwarding eliminates all of these issues. VSLStats captures events at the server level (plays, completions, CTA clicks, conversions) and forwards them to your chosen ad platforms using their server-to-server APIs. No browser required.

Industry benchmark: Teams switching from browser-only to server-side forwarding typically recover 15–35% of previously lost conversion signals. This directly improves ROAS reporting and ad algorithm optimization.

Connecting Meta Conversions API (CAPI)

In VSLStats, go to Settings → Integrations → Meta CAPI.
Enter your Meta Pixel ID (found in Meta Events Manager under your dataset).
Generate a CAPI Access Token in Meta Events Manager → Settings → Conversions API → Generate access token. Paste it into VSLStats.
Select which events to forward: ViewContent (play), VideoProgress (milestones), Lead (opt-in), Purchase (conversion).
Enable Event Deduplication - VSLStats sends a unique event_id so Meta can deduplicate if both browser and server events fire for the same action.
Click Save & Test. VSLStats will fire a test event you can verify in Meta Events Manager's Test Events tab.

Connecting Google Analytics 4 (GA4)

Go to Settings → Integrations → Google Analytics.
Enter your GA4 Measurement ID (format: G-XXXXXXXXXX).
Generate an API Secret in GA4: Admin → Data Streams → your stream → Measurement Protocol API secrets → Create.
Paste the API secret into VSLStats.
Map VSLStats events to GA4 event names. Defaults: video_start, video_progress, video_complete, generate_lead, purchase.
Save. Events will appear in GA4's DebugView within a few minutes during testing.

Connecting TikTok Events API

Go to Settings → Integrations → TikTok.
Enter your TikTok Pixel ID from TikTok Ads Manager → Assets → Events.
Generate an Access Token in TikTok Ads Manager → Assets → Events → your pixel → Settings → Generate Access Token.
Paste the token into VSLStats and select which events to forward.
Save and use the TikTok Event Tester to verify events are arriving.

Testing Your Setup

After connecting each platform, verify events are flowing correctly:

Meta: Use Events Manager → Test Events tab. Play your VSL on the actual page - you should see server events appear within seconds.
GA4: Use the DebugView report in GA4 Admin. Enable debug mode by adding ?ga4_debug=true to your page URL.
TikTok: Use the TikTok Pixel Helper browser extension or the Events Manager Tester tool.

Common issue: If you see duplicate events in your ad platform, ensure Event Deduplication is enabled in VSLStats. Both browser and server pixels may fire for the same action - deduplication uses the shared event_id to collapse them into one.

Privacy & Compliance

Server-side forwarding sends hashed user identifiers (email, phone, IP) to ad platforms for matching. Ensure your privacy policy discloses this data sharing. VSLStats automatically hashes all PII using SHA-256 before transmission - raw email addresses and phone numbers are never sent in plaintext.

For GDPR-compliant setups, use VSLStats' Consent Gate feature to pause event forwarding until the visitor accepts your cookie/tracking consent banner.