Check-in Calculator Back to the calculator

Privacy policy

Last updated:

This policy covers the Check-in Calculator website at rusewww.github.io/check-in_calculator and the Check-in Calculator extension for Google Chrome. Both are an independent, open-source project. In this policy, “we” means the project’s developer.

Summary

  • We do not collect, receive, sell or share any personal data.
  • There are no accounts, no analytics, no advertising, no tracking and no cookies set by this site.
  • Every calculation runs on your device, using your browser’s built-in time-zone database.
  • Your preferences are kept only on your own device, and you can delete them at any time.

What you enter, and where it is processed

To calculate when online check-in opens, you enter a departure airport, the scheduled departure date and time, the check-in window (for example, 24 hours) and, optionally, the time zone to show times in. These values are processed only in your browser. The list of airports is a static file: the website downloads it from this same site, and the extension carries it inside its package. Neither looks anything up on a server while you type.

What is stored on your device

Website

The website saves two small entries in your browser’s local storage:

  • checkin-calculator.settings: your theme (Auto, Light or Dark) and interface language.
  • checkin-calculator.zone: whether times follow the airport’s time zone, and the time zone you chose.

The website does not store your flight details. Instead, it puts them in the page address (for example ?apt=LHR&dep=2026-10-05T14:30&per=24h) so you can bookmark or share the result. Like any web address, it is kept in your browser history. To remove the saved entries, clear this site’s data in your browser settings.

Chrome extension

The extension saves the following in chrome.storage.local, which stays on your computer and is not synced to your Google account:

  • checkin-calculator.settings: your theme and interface language.
  • checkin-calculator.zone: your time-zone choice.
  • checkin-calculator.lastInput: the last airport, departure date and time, and check-in window you entered, so the popup reopens on your last answer.

Uninstalling the extension deletes all of this. Chrome’s “Clear browsing data” does not remove extension storage.

Network requests and third parties

Website hosting (GitHub Pages)

GitHub hosts the website on GitHub Pages. When you open a page, your browser requests it from GitHub’s servers. Like any web server, they receive your IP address, your browser’s user agent and the address you requested, including any flight details in a shared link. GitHub logs visitor IP addresses for security purposes, as described in the GitHub General Privacy Statement. We have no access to these logs, and the site uses no analytics.

Fonts (website only)

The website loads its Geist fonts from Google Fonts (fonts.googleapis.com and fonts.gstatic.com). As part of that request, Google receives your IP address and browser details. The site sends only its own origin as the referrer, so your flight details are not part of this request. See Google’s Google Fonts privacy FAQ. The extension includes its fonts in its package and makes no such request.

Add to Google Calendar (only when you click it)

This button opens calendar.google.com in a new tab with a pre-filled event. The event details travel in that address: a title with the airport code, the check-in opening time, the airport’s name and location, and a description with the opening and departure times and a link back to the calculator. Nothing is saved to your calendar until you confirm it on Google’s page. Google handles that data under the Google Privacy Policy.

Actions that stay on your device

  • Download .ics creates the calendar file inside your browser and saves it through your browser’s normal download.
  • Copy link writes a link with your current inputs to your clipboard. The clipboard is used only when you click this button. Nothing is sent unless you paste and open that link yourself.

Google Search Console

The website is registered in Google Search Console to confirm who owns it. Search Console shows us only aggregated statistics about how the site appears in Google Search results, such as how often it was shown or clicked. It does not identify visitors and adds no code or cookies to the site.

What the extension can access

The extension requests one permission, storage, which it uses to save the entries listed above. It requests no host permissions, so it cannot read or change the websites you visit. It runs no remote code and makes no network requests on its own. Links you choose to open from it, such as the one to this website, open in your browser as normal.

What we don’t do

  • We do not sell or transfer user data to third parties.
  • We do not use or transfer user data for any purpose unrelated to calculating when check-in opens.
  • We do not use or transfer user data to determine creditworthiness or for lending.

The extension’s use of data complies with the Chrome Web Store User Data Policy, including its Limited Use requirements.

Children

Check-in Calculator is not directed at children under 13. It does not collect personal information from anyone, including children.

Your choices

We hold no personal data about you, so there is nothing for us to access, correct or delete. Everything the website or extension saves is on your own device and under your control, as described above. To ask GitHub or Google about data they process, contact them under their own privacy policies.

Changes to this policy

If this policy changes, we will update the date at the top of this page and publish the new version at this same address. Every past version is public in the history of this page in the website’s source repository.

Contact

Questions about this policy or about how the website or extension handle data can be raised on the project’s GitHub issue tracker. Issues are public, so please don’t include personal information in them.