DNI (Dynamic Number Insertion)
What is DNI (Dynamic Number Insertion)?
Dynamic Number Insertion (DNI) is a script embedded on a webpage that swaps the phone number a visitor sees in real time, based on the marketing channel, campaign, or referrer that brought them there, then forwards any call placed to that number on to the business's real line. It turns the displayed number itself into the attribution signal, so an inbound call can be traced back to the exact ad, keyword, or campaign that drove the visit — the same way a UTM parameter attributes a form fill.
More detail
DNI draws each visitor's number from a pool of tracking numbers reserved for that purpose, keyed to the UTM parameters, referrer, or landing page that identified the traffic source, and swaps it into the page before it renders. A sticky variant keeps the same number for a visitor's whole session, so a return visit or a later call still resolves to the source that first brought them in.
Because the swap happens client-side and the underlying numbers still forward to the business's existing phone system, DNI adds no extra step for the caller — call quality and the destination are unchanged, only the number a given visitor sees differs from another visitor's.
Frequently asked
- Is Dynamic Number Insertion the same thing as call tracking?
- DNI is the mechanism, not the whole picture: it's the script that swaps in a different trackable number per visitor, session, or campaign. Call tracking is the broader practice — DNI plus the pooled numbers, call logging, and reporting that turns those swapped numbers into ROI attribution.
- Does a visitor notice anything different when DNI swaps their number?
- No. The swap happens before the page renders, so a visitor sees one phone number for the whole session — a sticky DNI setup keeps that same number if they return — and dialing it reaches the business exactly the way any other listed number would.
See also
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