Tealium iQ

Tealium iQ compiles your configuration into a utag.js bundle the page loads: a universal data object feeds load rules that decide which vendor tags fire, and JavaScript extensions transform values in between. Its integrations marketplace is among the largest in the category — Tealium counts over 1,300 pre-built integrations across the platform — and built-in consent management can gate tags by category before anything fires, with CMP integrations for OneTrust, Didomi, and Usercentrics. iQ rarely ships alone: Tealium positions it as the browser edge of a platform where EventStream handles server-side delivery and AudienceStream does CDP-style profile building, sharing the same data layer across web, mobile SDKs, and server.

How it models data. The page declares a flat JavaScript object, utag_data, before utag.js loads. At runtime Tealium merges it with values it collects itself — cookies, meta tags, query-string parameters, and other JavaScript variables — into a working data layer object that every extension, load rule, and tag mapping reads from. Page views fire via utag.view() and in-page events via utag.link(); a utag.link() call never loads new tags, only utag.view() does, and from utag.js 4.26 load rules are re-evaluated on each utag.view() — the mechanism single-page apps rely on.

Implementation notes. Execution order is fixed and worth learning early: Pre Loader extensions run before anything else (this is where consent prompts hook in), then the data layer is processed, then Before Load Rules extensions, then load rule evaluation, then After Load Rules, then tags fire (prioritized first, DOM Ready-scoped later), with tag-scoped extensions and mappings applied per tag. Each enabled tag ships as its own numbered file (utag.1.js, utag.2.js, …) requested asynchronously alongside the vendor’s own library, so one tag’s payload doesn’t block another. Publishing is environment-aware — Dev, QA, and Prod each get their own bundle URL.

Real gotchas. Extension scope mistakes are the classic failure mode: a value set in an After Load Rules extension can’t influence which tags load, and debugging means walking the order of operations rather than a single script. Default hosting is Tealium’s CDN (tags.tiqcdn.com); first-party self-hosting is supported — enable the distro.zip archive in publish configuration, point the Publishing URLs at your own domain per environment, and deploy after each publish (Tealium provides SHA-256 checksums to verify the files) — but confirm it’s in your contract first.

Migration considerations. Coming from GTM, expect to translate rather than copy: triggers become load rules, variables become data layer mappings, and GTM’s event-pushed dataLayer array gives way to the flat utag_data object plus explicit utag.view/utag.link calls. The console being SaaS while the bundle can live on your domain matters for CSP and ad-blocker planning.

That platform framing is also the cost. iQ is quote-priced enterprise software with a real implementation lift, and much of its value over a free container only materializes if you adopt the server-side and audience layers too.

Use it when you need vendor-neutral enterprise governance — one contract covering client-side tags, server-side delivery, and consent enforcement at capture. Look past it when a free container covers your needs, or your organization is already standardized on the Google or Adobe stack.