Frequently Asked Questions

Our tool uses real geographic boundaries from OpenStreetMap to display cities at their true scale. You can search for cities, add them to the map, and drag them around to compare their actual sizes side by side. The tool calculates areas using spherical geometry formulas that account for Earth's curvature.

Yes, you can search for and compare any major cities worldwide. Our database includes cities from all continents with their official administrative boundaries. Simply use the search function to find any city you're interested in comparing.

To move a city, simply click and drag on the colored city area. The city will maintain its relative geographic proportions while you move it. You can position cities next to each other to see their relative sizes clearly. The tool automatically adjusts the view to show all cities when you add multiple cities.

We use OpenStreetMap for city boundaries and geographic data, Nominatim for city search and geocoding, and cross-reference with official government sources to ensure accuracy of administrative boundaries. All data is publicly available and regularly updated.

Yes, Compare City Sizes is completely free to use. There are no hidden costs, subscriptions, or premium features. We believe geographic education should be accessible to everyone, and we're committed to keeping this tool free.

No, we don't store any personal information on our servers. Your city searches, comparisons, and preferences are saved locally in your browser on your device, so they persist between sessions. This means you can come back later and find your comparisons exactly as you left them. All of this data stays on your device and never leaves your browser—we have no access to it, ensuring your complete privacy.

We rely on OpenStreetMap data, which may not include all cities worldwide. If a city is missing, it might be because it hasn't been mapped in OpenStreetMap yet, or it might be too small to have official administrative boundaries. We're constantly working to improve our coverage.

Absolutely! Our tool is perfect for educational use. Teachers can use it to help students understand urban geography, city planning, and the relationship between population density and geographic area. It's a great resource for geography and urban studies classes at all levels.

We focus on official administrative city boundaries, which represent the legal city limits. Metropolitan areas include surrounding suburbs and can be much larger. Our tool shows the true administrative size of cities, which is often surprising compared to what people expect.

Our data is updated regularly as OpenStreetMap contributors add and improve geographic information. City boundaries and administrative areas are updated as changes occur in the real world, ensuring our tool reflects current geographic realities.