The short version
- Your sensor readings never leave your device. All the measuring happens in your browser.
- There’s no account, no signup and no app.
- A few settings and your own tool results are saved in your browser, never sent anywhere.
- Logger data stays in your browser until you delete it.
- Analytics, when turned on, are cookieless and count only page visits and a few named events.
- Ads from the Adsterra ad network may use cookies. They never load while a tool is measuring.
Your sensor readings
The motion sensor data (acceleration and rotation) is processed by code running on your phone. It’s never sent to our server or to anyone else. We don’t see your readings, and the site has no code to upload them.
Results you save go only where you send them:
- Save image, Download CSV and Download PDF report create files on your device.
- Share opens your phone’s own share menu, and you pick the app and the person. If your browser can’t share, a text summary is copied to your clipboard instead.
- The QR code shown on a computer is made in your browser. It holds only the address of the page you’re on.
The fonts and all the tool code load from this site’s own server, not from outside font or code services.
What’s stored in your browser
The site saves a few settings and results in your browser’s local storage. They aren’t cookies, hold no personal data and are never sent anywhere.
| Name | What it holds | Why |
|---|---|---|
| vc-theme | System, light or dark | So the theme you picked stays next time |
| vc-units | Your velocity unit (mm/s or in/s) and acceleration unit (g or m/s²) | So readings show in the units you picked |
| vc-tool-… (one per tool page) | The options and numbers you last entered on that tool page, like the test length, start delay, speed, tire size or RPM | So they stay filled in next time |
| vc-fan-balancer | Your fan-balancing setup and the runs in progress, with each run’s reading | So a reload keeps them |
| vc-pendulum-trials | Your pendulum trial results | So you can compare trials and download the worksheet |
| vc-pendulum-setup | Pendulum length, unit, recording time and start delay | So your setup stays filled in |
To remove them, clear this site’s data in your browser settings.
Logger data. The house vibration logger, construction vibration monitor and traffic and train test save their logs in your browser’s IndexedDB storage, so a log survives a page reload. Each event holds its time, peak velocity, frequency and duration, and a log also keeps the location or note you type for the report. The logs stay on your device. To erase them, tap “Delete all logs” on the logger page, or clear this site’s data in your browser settings. In a private or incognito window, they’re usually erased when you close it. On iPhone and iPad, Safari may delete saved logs if you don’t visit the site for a week, so download a CSV or PDF of logs you want to keep.
Analytics
We may use Plausible Analytics to learn which pages and tools people use, so we know what to improve. Plausible doesn’t use cookies, doesn’t store IP addresses, and can’t follow you across websites or from one day to the next. Its data is stored in the EU.
It counts page visits and a short list of named events: Start tapped, measurement completed, permission denied, no sensor, demo started and export used, along with the tool page it happened on. It never receives your readings.
Ads and cookies
The site is funded by native ads from Adsterra, an ad network. They show as small picture-and-title tiles between sections of a page and, on large screens, in the side column. The ad code comes from Adsterra’s servers. Adsterra and the advertisers it works with may set cookies or use similar technology in your browser to show ads, count views and clicks, limit how often you see the same ad and prevent fraud. Adsterra explains this in its privacy policy.
- Ads load only after you scroll or after a few seconds, and never while a tool is measuring.
- Ads never appear inside the tool panel, and your readings are never shared with advertisers.
- You can block or delete cookies in your browser, or use a content blocker. The tools work normally if you block ads.
Server logs
The site is hosted by IONOS. Like most web hosts, IONOS keeps standard server logs of each request: IP address, date and time, the page requested, the referring page and browser type. These logs help keep the site secure and running, and are kept for a limited time. We don’t use them to identify you or combine them with other data.
Children
The site isn’t aimed at children under 13. It doesn’t ask for personal information from anyone, children included. Teachers are welcome to use the pendulum experiment in class.
Your choices
- Clear this site’s data in your browser settings to remove your settings, saved tool results and logs.
- Tap “Delete all logs” on any logger page.
- Block or delete cookies in your browser.
- Use a content blocker. The tools still work.
Changes and questions
If anything here changes, we’ll update this page and the date below. Questions about privacy? Use the contact page. This page is written in plain English on purpose. It isn’t legal advice.
Last updated .