Tracker script

A ~1 KB cookieless script. One tag before </head>. No cookies, no localStorage identifiers, no fingerprints.

v5.js is the browser half of Vector 5. It counts people who execute JavaScript. Crawlers that never run JS are the middleware's job.

Install

index.html

<script defer data-domain="example.com"
  src="https://analytics.example.com/js/v5.js"></script>

The API serves the script at /js/v5.js (5-minute cache). You can also vendor packages/tracker/dist/v5.js and point data-api at your ingest host.

Framework recipesNext.js, WordPress, Shopify, Astro, Remix, SvelteKit, Webflow.Attributesdata-domain, data-api, data-hash.Custom eventswindow.v5 and data-v5-event.SPAspushState is already hooked.

What it sends

Field	JSON key	Source
Domain	`d`	`data-domain` or `location.hostname`
Event name	`n`	`pageview` unless you pass one
URL	`u`	`location.href`
Referrer	`r`	`document.referrer`
Hostname	`h`	`location.hostname`
Screen width	`w`	`screen.width`
Props	`p`	Optional object from `window.v5`
UTMs	`utm_*`	From `location.search` if present

The server derives referrer host, country, device, browser, and OS, then discards the IP. The script never sends a visitor id.

Automatic events

Pageviews on load, pushState, replaceState, and popstate.
Hash changes when data-hash="true".
Outbound Link on clicks to another host.
File Download for pdf, zip, csv, xlsx, docx, png, mp4.
`data-v5-event` on any clicked element.

Ignore yourself

devtools

localStorage.v5_ignore = '1'

The script reads that key once at boot and exits. It is the only localStorage access, and it is opt-in on your machine. Ignore visits.