Legal
Effective 13 September 2026
VialMath is a calculator and tracker that runs in your browser or as an installed web app (PWA). It performs arithmetic and schedule logic on the numbers you enter. It does not collect, transmit, or store your protocol data on any server we operate, except as described below for the one-time license check.
1. The license check, once, at activation. That check transmits your
license key — not your protocol data, not your compounds, doses, schedules, vial
history, gate checks, or metric log. It goes to Gumroad's license server
(api.gumroad.com); VialMath operates no server and receives nothing from it,
and Gumroad's handling of the request is governed by Gumroad's privacy policy. We do not
log or retain IP addresses — we have nowhere to log them.
2. The update check, when the app opens or returns to the foreground.
VialMath fetches its own version.json from the same address it was
loaded from, and compares the build number with its own. If a newer build exists it
shows you a banner. The request carries no license key, no identifier, no cookie
and no protocol data — it is the app asking what version it should be. It exists
because VialMath installs as a PWA, and a stale cached copy is otherwise invisible:
you would go on using an old build believing it was current, which for a calculator
is the worst failure available.
Disclosed 2 September 2026, on this page's own terms. The section below committed us to disclosing "any future release [that] adds a recurring call of any kind (a re-validation check, an update check…)". The update check had shipped and this page had not caught up. An independent audit of our own claims found it, and this is the correction. We have not removed the check — it protects you from running stale arithmetic — but the earlier wording, "the only network call", was wrong, and any page of ours that still says "only" is wrong until fixed.
There is one place on this site where we can receive something about you: an optional signup form on the free calculator page. It is not part of the app, it is never required for anything, and no feature is gated behind it.
If you use it, we store your email address, which page you signed up from, and the date. Nothing else — no IP address, no device information, no cookies, no profile. It is kept on Cloudflare Workers KV.
We do not sell, rent, share, or broker this list, to anyone, for any price — and specifically never to anyone selling anything. This is not a preference we may revise for a good offer; addresses collected under this promise stay under it permanently, and a future change to this page would not release them.
We use it for one thing: telling you when there is a new free tool or an app update. Every message has a one-click unsubscribe and we honour it immediately. Ask us to delete your address at any time — write to [email protected] and it is removed.
Your protocol data has nothing to do with this. It stays on your device, is never linked to your email address, and is never transmitted to us — signing up changes none of that.
Everything you enter — compounds, phases, cycles, vial events, dose logs, gate checks and decisions, blends, metric entries — is stored locally on your device, using your browser's own local storage. It stays there until you delete it, clear your browser's site data, or export it yourself.
You can export a full backup (JSON), a spreadsheet-ready CSV, or a calendar file (.ics) at any time, from the app's Data view. Your data is never locked in.
We do not claim VialMath is "fully offline," makes "no network calls," or involves "zero telemetry" — the license check and the update check are real network calls, and this page discloses both plainly rather than rounding them away. If that changes — if any future release adds another recurring call of any kind (a re-validation check, crash reporting, anything that carries an identifier) — this policy will be updated in the same release, not after.
The marketing site (this page, the calculator, the comparison page) receives standard, non-identifying web server access logs from our hosting provider, as essentially every website does. We also run our own page counter on these pages, described under “What we do not do” above: it records that a page was viewed and which site linked to it, and nothing else. We do not use advertising pixels, third-party trackers, or any third-party analytics service anywhere on this site.
Purchase and referral links go through Gumroad, which runs the checkout: a referral link sets Gumroad’s own cookie, on gumroad.com, for up to 30 days so Gumroad can credit the person who sent you; that cookie is Gumroad’s, is governed by Gumroad’s privacy policy, and never touches this site or the app.
VialMath is not directed at, and is not intended for use by, children.
13 September 2026 — Added one sentence under “The site itself” disclosing that purchase and referral links go through Gumroad and that a referral link sets Gumroad’s own 30-day cookie on gumroad.com. Nothing we collect changed; the sentence describes a cookie set by Gumroad, on Gumroad, that never reaches this site or the app. The prior version is kept at /privacy/versions/privacy-2026-09-13.html.
1 September 2026 — Corrected an inconsistency in this policy. The section “The site itself” said we add no analytics to the site, while the section above it described the first-party page counter we have run on our marketing pages since 29 August 2026. The counter and its limits were disclosed here before it recorded anything; the conflicting sentence has been corrected to match. No data practice changed, and nothing we collect has ever included a cookie, IP address, user agent, fingerprint, or identifier of any kind.
If this policy changes, we will update the date at the top of this page. We will not narrow a privacy commitment retroactively without saying so plainly here.
Questions about this policy: [email protected].