Privacy & Cookies

Last updated 9 August 2026

The short version.

Your diagrams never leave your browser — there is no account, no server and no database behind GravelGraph. We measure visits with cookieless analytics. The only cookies are advertising cookies from Google, and those are set only if you press Accept on the cookie banner.

Who this is about

GravelGraph is a free, browser-based tool for drawing architecture and data-flow diagrams, available at www.gravelgraph.com. If you have a question about anything on this page, or want data removed, email [email protected].

Your diagrams

Everything you draw is created and stored in your own browser. Diagrams are never uploaded, and we cannot see them, recover them or share them.

Autosave keeps your current diagram in your browser's local storage so it survives a reload. Clearing your browser's site data deletes it permanently.
Saved files (.gravel) are written to wherever you choose on your own device.
Share links carry the whole diagram inside the URL's fragment (the part after #). Browsers never send a fragment to the server, so a shared diagram still doesn't reach us — but it is inside the link, so anyone you give the link to can open the diagram. Treat a share link as you would the diagram itself.

What we store in your browser

These are local-storage entries, not cookies — they stay on your device and are never transmitted:

diagramr.autosave — your current diagram
diagramr.autosave.recovery.<timestamp> — if a saved diagram is ever found corrupted, a copy of it before anything is overwritten (up to the 3 most recent); the app never reads these back automatically, they're just kept so nothing is silently lost
diagramr.stencils — components you saved for reuse
diagramr.layout — panel sizes and collapsed state
diagramr.theme — light or dark
diagramr.insights — whether the insights panel is on
diagramr.seenWelcome, diagramr.seenStorageNote — so one-time prompts stay dismissed
diagramr.cookieConsent — your answer to the cookie banner

GravelGraph is also an installable offline app, so your browser keeps a cache of the app's own files (not your diagrams). Clearing site data removes all of the above.

Analytics

We use Plausible Analytics, self-hosted on our own infrastructure. It is cookieless and collects no personal data — just aggregate counts of page views, referrers, countries, browsers and device types. It does not track you across sites and cannot identify you. Diagram data in the URL fragment is deliberately excluded from what it records.

Advertising and cookies

GravelGraph is free because it shows ads through Google AdSense. Google may set cookies to personalise ads, cap how often you see the same ad, and measure performance and fraud.

Until you answer the cookie banner, ad personalisation and ad storage are set to denied, and Google is instructed not to store or read ad cookies.
Press Accept and Google may set those cookies and personalise ads.
Press Decline and you'll still see ads, but generic, non-personalised ones.
You can change your answer at any time: open Help in the app (the ? button) and choose Cookie settings.

How Google uses this data is described in How Google uses information from sites that use its services. You can also manage personalisation directly at My Ad Center.

Server logs

Like any website, our web server records standard request logs — IP address, timestamp, requested file, referrer and browser user-agent — for security and troubleshooting. These are not used to build a profile of you and are not combined with analytics.

Third parties

The only third parties involved in a normal visit are:

Google AdSense — advertising — privacy policy
Plausible Analytics — self-hosted by us, so no data goes to a third party

We do not sell or share your personal information, and there is nothing to sell.

Your rights

Depending on where you live, you may have rights to access, correct, export or erase your personal data, and to withdraw consent. In practice, because there are no accounts:

Erase everything we hold locally — clear site data for gravelgraph.com in your browser settings.
Withdraw ad consent — Help → Cookie settings, then choose Decline.
Anything else — email [email protected] and we'll respond.

Children

GravelGraph is a tool for engineers and isn't directed at children. We don't knowingly collect personal information from anyone under 13.

Changes

If this policy changes in a way that affects what we ask your consent for, the cookie banner will ask again. Otherwise the date at the top will tell you when it last changed.