A lightweight, production-ready solution for dynamic phone number insertion based on UTM parameters. Built for marketers and developers who need reliable call attribution without monthly SaaS fees.
What It Does Automatically swaps phone numbers on your website based on traffic source, campaign, or any UTM parameter. When someone clicks your Google Ad, they see a different tracking number than someone coming from Facebook or email campaigns. Key Features:
UTM-based phone number switching (source, medium, campaign, etc.) CSS selector-based targeting for precise control Cross-page UTM persistence with configurable expiration Dynamic content support (SPAs, AJAX sites) Automatic link (tel:) updates Zero external dependencies
Quick Start
Add to GTM: Copy the script into a Custom HTML tag Configure: Edit the mappings for your campaigns Deploy: Set trigger to "All Pages" and publish Test: Visit with UTM parameters to see numbers change