Trust
Privacy
This page lists exactly what Runlight stores and never stores, and explains why a site using it needs no cookie banner.
Runlight is built so that it never needs to know who anyone is.
How visitors are counted
Each day Runlight makes a new random salt. A visitor is the SHA-256 hash of that salt, your site, the visitor’s IP address, and their browser’s user agent, cut to 64 bits. The same person on the same day gets the same value, which is how visitors and visits are counted. Tomorrow they get a different one.
A site’s salt changes at midnight in the site’s own timezone, so a visitor is one visitor for the whole of the site’s day, as its reports count days. A salt is kept until its day has ended in every timezone, and a day more so a visit that runs past midnight stays one visit, which means it is deleted within four days of when it began. Without the salt the hash cannot be recomputed or reversed, so from then on nobody, you included, can tell whether two visits came from the same person.
What is stored
For each visit, Runlight stores the hashed visitor, when it started and ended, the pages viewed, engaged time and scroll depth, the referring site and source, UTM tags, country, region and city, browser and version, operating system and version, device type, screen size, and language. For each event, it stores the event name and the properties you chose to send.
What is never stored
- IP addresses. They are used to make the daily hash and, where needed, to look up a country, then dropped.
- User agents. They are read for the browser, operating system, and device, then dropped.
- Cookies or anything in the visitor’s browser. The script stores nothing, except an opt-out flag you can set for your own browser.
- Any identifier that lasts longer than a day.
The law
Runlight is designed so that a site using it needs no cookie consent. It stores nothing on the visitor’s device, and what it keeps cannot be tied back to a person, which keeps it outside the GDPR’s idea of personal data. Because Runlight is self-hosted, your visitors’ data stays in your database on your servers and is never sent to anyone else.
This page describes how Runlight works. It is not legal advice. If you add properties to your events, keep personal details such as email addresses out of them.
Your own data
You own the database. You can query it and back it up like any other, and delete it whenever you like. Short link clicks and email report recipients live there too, and a report recipient can unsubscribe from any email.