Privacy and data handling

Overview

Last updated: May 5, 2026

This is a public map tool. It does not require an account and it is not designed as a social, messaging, or saved-drawings platform. Even so, some technical data is processed when you load the site, use the drawing tools, request a population estimate, or view ads.

What the service processes

When you visit the site, the hosting, reverse-proxy, and application infrastructure necessarily receive technical request data such as IP address, browser and device information, requested URLs, timestamps, HTTP status information, referrer data, and basic error or security events. This is standard for delivering pages, preventing abuse, and troubleshooting service problems.

What happens when you draw an area

When you draw a polygon or circle, the browser sends the resulting geometry to the API so the service can estimate the population inside that area. The geometry is processed for the requested calculation and is not offered as a public saved drawing feature for other visitors.

Please do not use the drawing tool to intentionally submit notes, names, or other sensitive personal information. A drawn area can itself be sensitive if it identifies a home, workplace, or another private location.

Map and tile providers

The interactive basemap uses external style and tile infrastructure from OpenFreeMap, OpenMapTiles, and OpenStreetMap-based services. Those providers can receive standard web request data such as IP address, user agent, and the map resources your browser requests.

Advertising (Google AdSense)

The site is funded by ads delivered through Google AdSense. As a result, third-party vendors, including Google, use cookies, web beacons, IP addresses, and similar identifiers to serve, measure, limit, and where applicable personalize ads based on a user's prior visits to this site or other sites on the Internet.

Google's use of advertising cookies enables it and its partners to serve ads to users based on their visit to this site and/or other sites on the Internet. If third-party vendors or ad networks other than Google are used to serve ads through Google's systems, those vendors may also place and read cookies on users' browsers and use web beacons or IP addresses to collect information as a result of ad serving.

For more details about how Google uses information from sites or apps that use Google services, see How Google uses data when you use our partners' sites or apps.

Users in the European Economic Area, the United Kingdom, and Switzerland see a first-party privacy notice with accept and decline options before optional analytics scripts load. Google AdSense may also show a consent message before personalized ads or ad-related cookies that require consent are used, in line with Google's EU User Consent Policy. Visitors can change their choices through that Google message when it appears, through the controls listed in the "Your choices and rights" section below, or by clearing the site's saved choice on the Cookies page.

Analytics

Optional aggregate analytics (Cloudflare Web Analytics and Google Analytics) load only if you accept them in the first-party privacy notice. According to Cloudflare's product documentation, Cloudflare Web Analytics does not use cookies or localStorage for its measurement.

Cookies and local storage

The site itself does not currently set first-party cookies for core map or population-calculation features. It does store a small amount of browser localStorage for UI preferences, currently the selected area unit (population-polygons-area-unit), whether the pen hint has been dismissed (population-polygons-pen-hint-dismissed), and your answer to the optional analytics notice (pc_privacy_consent_v1, either accepted or declined).

The separate Cookies page in this section gives a more detailed breakdown of site storage and third-party ad technology.

How the data is used

The processed data is used to render the map, calculate population estimates, remember lightweight UI preferences, protect the service with rate limiting and abuse controls, monitor uptime and performance, and display or measure advertising.

Retention

The service is not designed as an account or history product, so it does not intentionally provide saved drawings to end users. To speed up repeat calculations, recent results may be kept briefly in an in-memory cache keyed from a normalized geometry hash and year. Infrastructure logs and security events may also be retained for limited periods according to server and provider settings.

International transfers

This service relies on third-party providers that may process data in countries other than your own, including the United States and other regions where Google, Cloudflare, hosting providers, or map providers operate.

Your choices and rights

You can stop sending drawn geometry by not using the draw tools, clear localStorage in your browser, and manage cookies through your browser settings.

You can opt out of personalized advertising by Google by visiting Google Ad Settings. You can also opt out of personalized advertising from many third-party vendors by visiting aboutads.info/choices (Digital Advertising Alliance) or, in Europe, youronlinechoices.eu. Additional information about Google's advertising cookies for publishers is available here.

If you are in the European Economic Area, the United Kingdom, or Switzerland, you can change or withdraw the consent choices you made in Google's consent message at any time when it appears. You can also clear or change your saved choice for optional analytics using the controls on the Cookies page. Withdrawing consent does not affect the lawfulness of any processing carried out before the withdrawal.

Depending on where you live, you may also have privacy rights such as access, correction, deletion, restriction, objection, portability, withdrawal of consent where consent is the basis for processing, and the right to complain to a supervisory authority.

For privacy questions or rights requests, contact the site operator at populationcircle@gmail.com.

Changes

If the project adds accounts, saved drawings, new analytics tools, different advertising technology, or other persistent user features, this policy should be updated to reflect those changes.