The browser enforces this, and you can check it
Every response from this site carries a Content-Security-Policy header, and while no advertising or analytics is configured that header sets connect-src to two Google addresses only, www.googleapis.com and oauth2.googleapis.com, which the page uses only after you press Save with Google. Every other outbound request this page could attempt — no fetch, no XHR, no WebSocket, no beacon, to any other address including ours — is refused by your browser. A page that tried would be blocked by the browser, not by our good intentions. Until you press that button the page makes no request to Google at all.
Saving with Google also lets the policy load Google's sign-in script and frame from accounts.google.com/gsi/, and the Cross-Origin-Opener-Policy header reads same-origin-allow-popups instead of same-origin, so that the Google window you open can report back to this page. Nothing else about the policy is loosened.
It is worth being precise about what that does and does not prove. It proves the PAGE cannot send anything anywhere. It does not cover the service worker, which is allowed to fetch this site's own files so the site works offline — that is the only exception, it is same-origin only, and it is written into the headers where you can read it.
To check: open your browser's developer tools, look at the response headers for any page here, and read the policy. Then watch the network tab while you use a calculator. If either ever disagrees with this paragraph, the paragraph is the thing that is wrong, and we would like to know.
What you type stays on your device
Every calculation on the site's pages runs inside your browser. Dimensions, quantities, prices, project line items and the contents of your estimate are computed locally and stored locally. None of it is transmitted to us: a page never sends your inputs anywhere. The one thing that can leave your browser is a copy you ask for yourself with Save with Google, described below, which goes to your own Google Drive.
This is a property of the architecture rather than a promise about our conduct. You can confirm it: open your browser's network inspector and use the site. No request carries your inputs until you press Save with Google.
The calculation service
Programs and AI assistants can ask the site's calculators for an answer directly, at api.craftquantities.com. A request carries the measurements the program sends; the answer is computed on Cloudflare's network, where the site and the service are hosted, returned, and forgotten. We keep no copy of the inputs or the answer, write no log of requests, use no cookies and ask for no account or key. Cloudflare, as the host, processes the request in order to deliver it, as it does for every page; its own terms cover that. If you use an assistant that calls the service, what you told the assistant is governed by that assistant's own policy, not ours.
What is stored in your browser, and why
The site uses your browser's own storage to remember your work between visits. This data is not readable by us, and it leaves your device only if you press Save with Google. Clearing your browser's site data removes all of it from this browser permanently; a copy you saved to your Google Drive stays there until you delete it.
- Your projects and their line items, including quantities, prices, notes and settings
- The values you last entered in each calculator, so returning to one does not lose your work
- Named presets you save on a calculator, and a short history of recent results
- Your chosen market, unit system and light or dark theme
- Prices you log in the Local Price Index, which is a private journal and is never pooled with anyone else's
- Saved project versions, held in IndexedDB because they can be larger
- Operator configuration, if you are running your own installation
Save with Google (optional)
If you press Save with Google in Settings, this site asks Google for one permission: to keep a single file in a hidden folder of your own Google Drive that only this site can open (Google calls it the app data folder). It does not appear in your list of files. The site can see no other file in your Drive and does not ask for your name, your email address or your contacts.
The file holds what the backup file in Settings holds: your projects and their lines, prices, saved estimate versions, job history, letterhead, clients and suppliers, templates and the other things the backup carries. It never holds the site's admin settings or your Google sign-in.
We cannot see it. It goes from your browser to Google and back; there is no server of ours in between, no database and no copy. Google keeps it under its own terms and the security of your Google account. Your Google sign-in is held in this tab's memory only and is gone when you close or reload the tab: the site remembers only that you connected before, so it can ask you to press the button once.
Until you press the button this site makes no request to Google for this: Google's sign-in script is fetched only when you press it. Google's sign-in window is Google's page, and Google sets its own cookies there under its own terms.
To stop: press Disconnect in Settings, which stops saving, withdraws this site's access and keeps everything in this browser. To remove the file, press Delete my Drive copy there. You can also withdraw this site's access from your Google account at myaccount.google.com/permissions; the file then stays in your Drive until you delete it, which Google's own Drive settings (Manage apps) can do.
The field tools: camera, microphone and motion sensors
Several tools use your device's hardware. The bubble level and clinometer read the orientation sensors. The camera grid overlay opens the rear camera. The photo takeoff reads an image you choose. The acoustic analyser opens the microphone.
In every case the data is processed in the page and discarded. No photograph is uploaded, no audio is recorded to a file, no video frame is stored, and no sensor reading is transmitted. Your browser will ask permission before any of these can start, and you can withdraw it at any time in your browser's site settings.
Advertising
The site may display advertising supplied by Google AdSense. When it does, Google and its partners may set cookies and use device identifiers to select and measure advertising. That processing is Google's, under Google's terms.
Third-party vendors, including Google, use cookies to serve ads based on a visitor's prior visits to this website or to other websites. Google's use of advertising cookies enables it and its partners to serve ads to you based on your visit to this site and/or other sites on the Internet.
You can opt out of personalised advertising in Google's Ads Settings at adssettings.google.com. You can also opt out of some third-party vendors' use of cookies for personalised advertising at www.aboutads.info/choices or, in Europe, at www.youronlinechoices.eu.
How Google uses information from sites that show its ads is explained at policies.google.com/technologies/partner-sites.
If you are in the European Economic Area, the United Kingdom or Switzerland, you are asked for consent before any personalised advertising cookie is set, through Google's consent message, which is a certified consent management platform. Your choice is recorded and can be changed at any time from the Cookie preferences link in the site footer. Declining does not restrict any part of the site: every calculator works identically either way.
Analytics
This site runs no analytics: no page counter, no tracking pixel and no analytics cookie. If that ever changes, this section changes in the same build that switches it on.
What is never collected
To be specific rather than reassuring:
- No account of ours, no email address, no password — if you use Save with Google you sign in to Google, not to us, and we receive nothing from that
- No calculation inputs, results, project data or prices
- No photographs, audio, video frames or sensor readings
- No location data
- No payment information; nothing on this site is for sale
Your rights
Because no personal data reaches us, there is nothing held about you for us to disclose, correct or delete. The data that exists is in your browser and under your control: clearing site data erases it completely and immediately.
For the advertising cookies described above, Google processes the data under its own terms, and its policies set out how to exercise your rights with it.
Operator details
The legal entity operating this installation, its registered address and the applicable supervisory authority should be stated here before launch. They are deliberately absent rather than invented.