Pixel Auditor detects 21 distinct platforms — the Google, Meta, LinkedIn, and Microsoft stacks plus Segment, Tealium, Hotjar, Criteo, and Klaviyo (added in v2.4) — as well as the major server-side proxies. Each platform has its own extractId() function pulling measurement IDs from globals, dataLayer, script tags, and inline code.
Google
| Platform | ID format | Detection |
|---|
| Google Analytics 4 | G-XXXXXXX | gtag config, dataLayer, /g/collect |
| Google Ads | AW-XXXXX | gtag config, send_to, /g/collect with AW- prefix |
| Google Tag Manager | GTM-XXXXX | google_tag_manager[id], gtm.js script tag |
| Merchant Center | MC-XXXXX | send_to, /g/collect with MC- prefix |
| Universal Analytics | UA-XXXXX | flagged as retired — Google sunset July 2024 |
Meta
| Platform | ID format | Detection |
|---|
| Meta Pixel | 15–16 digit ID | fbq globals, fbevents.js, /tr/ requests, fbq() hooks |
| Meta CAPI Gateway | — | /tr/ path on non-Meta first-party host with vendor-specific param signature |
LinkedIn
| Platform | ID format | Detection |
|---|
| LinkedIn Insight | partner_id: NNNNN | _linkedin_partner_id, _linkedin_data_partner_ids, insight.min.js, px.ads.linkedin.com |
Microsoft
| Platform | ID format | Detection |
|---|
| Bing UET | UET tag ID | _uetq, UET() constructor, bat.bing.com/bat.js, uetq.push() hooks |
| Microsoft Clarity | Project ID | clarity global, clarity.ms/tag, clarity() hooks |
CDP, TMS & behavior platforms (added in v2.4)
These five vendors queue calls in a stub and flush them after their library loads, so they are detected by network, script, and ID-extraction signals (the same approach as LinkedIn) rather than JS-API hooks — this avoids double-counting against the network interceptor.
| Platform | ID format | Detection |
|---|
| Segment | Write key | loader URL, analytics._writeKey, analytics.load(…); cookies ajs_anonymous_id, ajs_user_id |
| Tealium | account/profile/env | tiqcdn utag path or utag.cfg.path; cookies utag_main* |
| Hotjar | hjid | _hjSettings, hotjar-<id>.js; cookies _hjSession*, _hjid |
| Criteo | Account ID | criteo_q setAccount or inline; cookies cto_* |
| Klaviyo | Company ID | company_id=, /onsite/js/<id>/klaviyo; cookie __kla_id |
Pre-consent fires from all five are classified and flagged just like the headline platforms.
Server-Side Tracking
Beyond the named platforms above, Pixel Auditor's Server-Side Tracking detector identifies fires routed through first-party proxies and vendor server APIs. These are detected by classification rather than enumerated as headline platforms — Pixel Auditor surfaces the actual proxy domain and the vendor it's forwarding to, regardless of which SaaS or self-hosted setup is in use.
| Category | How it's detected |
|---|
| First-party proxy for Google (sGTM) | Custom domain forwarding to canonical Google collect endpoints with a valid vendor tid prefix — including renamed request paths (caught by Measurement Protocol signature, v2.3.1) and base64-encoded transports (v2.4.1) |
| First-party proxy for Meta | Vendor-shaped /tr/ request on a non-Meta host with valid pixel-ID + event-name params |
| Vendor server APIs (event-id pattern) | Script-text and runtime hooks for known server-side conversion APIs |
| Edge-tag / hosted sGTM platforms | Brand-owned subdomains and edge endpoint paths |
For the full architecture of how the SST classifier works, see Server-side tracking detection.