What this site
knows about you.
Almost nothing, and this page says exactly what. There are no accounts, no cookies, and no ad networks here. The tools do their work inside your browser, so what you type into them is handled on your own device and never sent to me.
Last updated 18 August 2026
The short version
If you read nothing else- No sign-up, no login, no account. There is nothing for me to hold.
- No cookies, from me or anyone else. Nothing to consent to.
- Nothing you type, upload, or open in a tool is sent anywhere.
- I count page views anonymously. I cannot tell who you are or link two visits together.
- Three pages do reach outside your browser, and they are named below.
- No data is sold, rented, or shared. There is no one to share it with.
What I collect
Two things1. Anonymous page views. Most pages load Cloudflare Web Analytics, which counts visits and tells me which pages people open, roughly which country a visit came from, and what kind of browser was used. It sets no cookies, writes nothing to your device, and does not fingerprint you. I get totals, not people. I cannot tell one visitor from another, cannot follow you between pages, and cannot follow you off this site.
Every page carries it, including the tools that handle something private.
What the beacon can see is the address of the page and nothing else. It reads the
path, so /qr/ or /instagram/ is the whole of it. It does not read
the part of a link after ? or #, which is why the Shortcut link
that prefills a WiFi password and the Nertz share link never reach it. It cannot see what
you type, what you upload, or what a tool works out. No tool's own code can make a network
request at all, which is the part a test enforces on every change.
2. Ordinary server logs. The site is hosted on Cloudflare Pages. Like every web host on earth, it records the requests it serves: IP address, timestamp, the page requested, and the browser's user-agent string. Cloudflare keeps these briefly for security and abuse handling, under its own privacy policy. I do not have a per-visitor log to read, and I do not build one.
What stays on your device
And only thereSome tools remember things between visits. All of it is written to your
browser's localStorage, which is storage on your own machine. It is never
transmitted, and I never see it.
- Light or dark theme, on every page.
- Instagram tool: the snapshot you set as a baseline, and your ignore list.
- Life in Weeks and Time Left: the birthdays and names you entered.
- Nertz and Tractor: the running game and player names.
- Various tools: small view and sort preferences.
Every tool that saves something has its own reset, and clearing site data for kelvinct.com in your browser wipes all of it. Since none of it ever reaches me, there is nothing for me to delete on your behalf.
The three places data leaves your browser
Every page carries a Content Security Policy that names the one host the page-view ping goes to and permits nothing else, so the browser itself blocks any other destination, whether I want it to or not. On top of that, no tool's own code can make a network request, so what you type has nothing to travel on. Three surfaces are different, and pretending otherwise would make this whole page worthless.
1. The watershed map, at /huc. A map has to fetch a map. Searching a place sends what you typed to OpenStreetMap's Nominatim geocoder, the map tiles come from OpenStreetMap, and the watershed lookup queries the USGS National Map. Those services see your IP address and what you looked up, under their own policies.
2. The LINE sticker tool, at /sticker. Reading a sticker pack means reading
its images, and those images live on LINE's servers. Your browser fetches them straight
from LINE, so LINE sees your IP address and which pack you opened. The images never
pass through kelvinct.com, and which pack you opened is never part of the page-view
ping, which records the address /sticker/ and nothing more.
3. Dash, at dash.kelvinct.com. Dash is a genuinely different animal: a connected service on its own domain that holds encrypted WHOOP and Oura tokens and your recent numbers on a server. Nothing on this page applies to it. It has its own privacy policy, and the reasons are explained here.
The Mac app is a separate thing
KelvinXDRKelvinXDR is a macOS app, not a page on this site. It makes no network calls at all, so there is nothing for it to collect and nothing for me to receive, and that is a property of the code rather than a promise on a policy page.
This policy covers this website, so it does not govern the app. That is the job of its licence and of the privacy section on its own page, which goes into the detail and is the copy kept current. Read that one before you install it.
If you email me
[email protected]Then I have your email address and whatever you wrote, sitting in my mailbox like any other email. I use it to reply to you. I do not add it to a list, because there is no list. Ask me to delete a thread and I will.
Don't take my word for it
Go and checkThis is the rare privacy claim you can verify yourself in about a minute. Open any tool, press F12, go to the Network tab, and use it. You will see the page's own files load and exactly one extra line, the Cloudflare beacon, carrying the address of the page. Then type into the tool, and watch: nothing further goes out. What you will never see, on any page except the three named above, is anything you typed going anywhere.
The whole site is public on GitHub, so you can read the code rather than trust the copy. A test runs on every change that fails the build if a tool's policy ever names a host beyond the beacon, if tool code gains a network call, or if any page starts loading a script from somewhere else. The guarantee is enforced, not just promised.
Changes and contact
Ask me anythingIf any of this changes, I will change this page and move the date at the top. Questions, corrections, or a request about your data go to [email protected]. If you are in a place with laws about access, correction, or deletion, write to me and I will do what they require, which in practice is usually to confirm that I am not holding anything of yours.