privacy

Privacy notice

Last updated 27 September 2026.

Spare Key is designed to collect as little as possible. There are no accounts and no cookies, and it never asks for passwords.

Who is responsible

Spare Key is run by Jonathan Harbourne (JHarbourne.com), who is the data controller for the limited processing described here. Contact: hello@jharbourne.com.

What stays in your browser

Everything you type into Spare Key, such as names, contact details, services and notes, is kept only in your browser’s local storage on your own device, so you do not lose your work. It is not sent to us. “Start again” deletes it. Your light or dark choice is stored the same way.

Domain lookups

Lookups run in your browser. Spare Key has no server that receives them. Your browser sends only the domain name, and only to public lookup services: Cloudflare’s public DNS, IANA’s list of registries, the registry for the domain’s ending (such as Nominet or Verisign), and Cert Spotter’s public log of security certificates. Those services have their own privacy policies. Spare Key never connects to the website itself. The page’s security policy stops your browser sending anything to any other address. See how to check this yourself.

Usage counts

We use PostHog, hosted in the EU, to count how features are used, for example how many handover documents are downloaded. It is set up so that it:

• sets no cookies and stores nothing on your device;
• builds no profile of you and records no sessions;
• receives only a short list of named events with numbers, never domain names, client names or anything you type;
• does not keep your IP address;
• does not run at all if your browser sends a Do Not Track signal.

The legal basis is our legitimate interest in understanding which features are useful. The data cannot identify you.

Feedback

The feedback board is run on the Nearmark website, which is also run by Jonathan Harbourne. Posting an idea needs an email address for a sign-in link, and is covered by that site’s privacy notice.

Your rights

Because we hold no personal data about you, there is usually nothing to access or delete. If you think we do hold something, contact us at the address above. You can also complain to the Information Commissioner’s Office (ico.org.uk).