Privacy policy
Nothing you type into a calculator on this site leaves your browser.
Last updated
The short version
StowMath does not sell your data, has no account system and carries no advertising at the time of writing. Every calculator runs entirely on your own device, and nothing you type into one is ever sent anywhere. The one thing the site does measure is traffic - which pages get visited, from roughly where - using Google Analytics, described in full below.
Your calculator inputs
When you type dimensions, weights, costs or duty rates into a calculator on this site, those numbers are processed by JavaScript running in your own browser. They are never transmitted to a server, because there is no server to transmit them to - StowMath is a static site with no backend, no API and no database.
This is a deliberate design decision, not an oversight. Shipment details are commercially sensitive: carton counts, container volumes and landed costs describe an order that may not be public yet. The safest way to handle that data is to never receive it.
Share links
Each calculator writes your inputs into the page address as you type, so that you can copy the link and send a result to a colleague or forwarder. That happens locally in your browser's address bar. The link is only shared if you choose to share it - but be aware that once you send it, the numbers in it are visible to whoever receives it, and to any system that link passes through.
Cookies and local storage
StowMath sets two cookies, both belonging to Google Analytics and both used only to count visits.
_ga- a randomly generated identifier that lets Analytics recognise a returning browser rather than counting it as a new visitor each time. It expires after two years._ga_LVEZ47Y1W8- holds the state of the current visit for this specific site. It also expires after two years.
Neither contains anything you typed, and neither is used for advertising or sold to anybody. Blocking cookies for this domain, or using any content blocker that stops Google Analytics, costs you nothing - every calculator keeps working exactly as it does now.
It uses one localStorage entry, stowmath-theme, which records whether you chose the light or dark theme so the site does not flash the wrong one on your next visit. It contains the word light or dark and nothing else. It never leaves your device and it is not an identifier. Clearing your browser storage removes it, after which the site simply follows your operating system setting.
Third parties
One. Loading a page causes your browser to contact Google, which supplies the Analytics script. Fonts are served from this domain rather than a font CDN, and there is no embedded video, no social widget and no advertising code, so Google is the only other company involved.
Google Analytics
Analytics tells us how many people reach each calculator and roughly where from, which is what decides which tool gets built next. It records the page you viewed, an approximate location derived from your IP address, and basic device and browser information. It does not receive your calculator inputs - those never leave your browser, including the numbers in a share link.
The data is processed by Google under Google's privacy policy. You can opt out across every site that uses Analytics with Google's official opt-out add-on, or simply block the domain googletagmanager.com.
Server logs
The site is hosted on Cloudflare Pages. Like any web host, Cloudflare processes the technical request data needed to serve a page - IP address, user agent, requested URL, timestamp. StowMath does not have access to per-visitor logs and does not use this data for profiling. It is governed by Cloudflare's own privacy terms.
Advertising
There is no advertising on this site today. The intention is to apply for Google AdSense once the site is established, and advertising is the planned business model - there is no paid tier and no plan to sell data.
If and when advertising is introduced, it will set cookies and this page will be updated before any ad code goes live, with the specifics of what is set and how to control it. Until you see that update, the statements above hold.
Children
This site is a professional tool for people working in freight and trade. It is not directed at children and collects no data from anyone, including children.
Changes to this policy
Any material change will be reflected in the last-updated date at the top of this page. The rule this site holds itself to is that the page is updated in the same change that alters what is collected, never after it - Analytics was added that way, and advertising will be too.
Contact
Questions about privacy, or anything else, go to hello@stowmath.com.