Last updated: 28 August 2026
FireWise operates this website and is the data controller for the personal data described below. Contact for privacy matters: privacy@firewisehq.com.
Nothing you type into a calculator ever reaches us. There are no
accounts and no sign-up. All calculator inputs are processed in your browser and
stored only on your device (local storage), so the app can restore your last values.
Technical logs — our hosting provider keeps short-lived server logs
(IP address, request path) for security and abuse prevention (legitimate interest in
keeping the service secure).
Embedded widgets — when one of our embeddable calculators or charts
loads on someone else's website, we record the domain name of that website so
we know where our widgets are used (legitimate interest in understanding how the embed
programme is used). That is a fact about the publisher's site, not about you: no IP
address, browser or page address of yours is stored with it.
FireWise shows no advertising and needs no cookies to work. Our analytics processor is PostHog, hosted in the EU, and it runs at one of two levels with a different legal basis behind each.
Anonymous audience measurement — Art. 6(1)(f) GDPR, legitimate interest. Unless you have chosen "Essential only", we count page views and where visits come from. This level sets no cookie and writes nothing to your device's storage, so it does not require consent under Art. 5(3) of the ePrivacy Directive; visitor numbers come from a one-way hash that PostHog's servers compute from your IP address and browser, with a salt that is rotated and discarded daily, and that cannot be reversed into personal data. Your IP address is used only to compute that hash: it is not retained against the event and is not resolved into a location, so no country or city is recorded. Our legitimate interest is knowing which pages and calculators are worth maintaining. Nothing else is collected at this level, and you can object at any time — that is exactly what "Essential only" does.
Full analytics — Art. 6(1)(a) GDPR, consent. If you choose "Accept analytics" in the cookie banner, PostHog additionally records clicks and interactions with the calculators, technical error reports, and session recordings where we have them enabled, and stores a random identifier in a cookie and local storage to count visitors and sessions across visits. We do not link it to any name or account (we have none) and do not use it to identify individual visitors. Where recordings are made, form inputs are masked in your browser before anything is sent. You can withdraw or change your choice at any time on the Cookie Policy page.
Separately, and independently of your choice, our own server records an error report when a page fails to render, and logs when the exchange-rate endpoint is called. These are generated on the server, are not tied to a device identifier, and rest on the same legitimate interest in keeping the service working.
The app also keeps a few functional items in your browser's local storage — your display currency, recently used calculators and your last calculator inputs — which stay on your device and are not used for tracking. Every item is listed in the Cookie Policy.
We share data only with the infrastructure needed to serve the site: our hosting/CDN provider (Cloudflare), which processes standard technical request data (IP address, user agent) to deliver pages and protect against abuse, and our analytics processor (PostHog, hosted in the EU). PostHog receives the page URL, referrer and browser type for anonymous counting; only after you consent does it also receive interaction events, error reports, any session recordings and a random device identifier. The site's typefaces are self-hosted and served from our own servers, so your browser makes no third-party request to load them and no font provider receives your IP address. Where a processor is outside the EEA, transfers rely on an adequacy decision or EU Standard Contractual Clauses.
We hold no user database. Technical logs roll off automatically after a short period. Data in your browser's local storage stays until you clear it.
Under the GDPR you can request access, rectification, erasure, restriction, portability, and object to processing based on legitimate interest — contact us at privacy@firewisehq.com. You can withdraw your analytics consent, and object to the anonymous measurement described in section 3, at any time by choosing "Essential only" on the Cookie Policy page, with effect for the future. Beyond analytics events and short-lived technical logs we store no personal data about you, so in most cases there is simply nothing further to retrieve or delete — and the anonymous measurement holds no identifier we could use to find your records. You also have the right to lodge a complaint with your local supervisory authority.
We will announce material changes to this policy on the site before they take effect.