Your curiosity
stays yours.
You can explore Just How Big? without an account. Measurements and games run in your browser. The site does not use fingerprinting to identify visitors.
Preferences on your device
Your browser can remember your preferred units, game settings, Daily 5 first attempts and streaks, and your analytics choice. These preferences stay on this device and are not synchronised to an account.
You can remove them by clearing this website's data in your browser settings. This also clears your saved results and analytics choice. A small amount of temporary browser storage prevents the homepage logo animation from replaying during a visit.
Optional analytics
Google Analytics 4 and Cloudflare Web Analytics help us understand how the website is used and what needs improving. Neither loads until you choose to accept analytics. You can reject them and continue using the site.
If you accept, usage information is sent to Google and Cloudflare. This can include pages visited, browser and device information, and website performance. Google Analytics also receives selected interactions, such as submitted search terms, comparisons, game settings and scores, shared-link actions, support-link clicks and worksheet downloads. Please avoid entering personal information into search.
Google Analytics uses cookies to recognise visits. Your choice is saved in your browser so you do not have to answer on every page. Advertising storage and advertising personalisation are set to denied.
Use Cookie settings here or in the footer to change your choice. Rejecting after acceptance stops further measurement, reloads the page and attempts to remove the site's Google Analytics cookies. It does not erase information already received by the providers.
Hosting and shared links
Cloudflare hosts the site and handles page and file requests. These requests can include your IP address and browser information, and the hosting provider may keep operational logs. This is separate from optional analytics. Any authentication used for a private preview is also separate from the public atlas.
Custom comparisons and game challenges can save their settings in a shared link. Anyone with the complete link can read those settings. A game challenge includes its version, random seed and setup choices, not your answers or score. Do not put private information in a link you share.
External services
Illustrations and fonts are served with the website. Interactive comparisons embedded in stories load from Just How Big?, rather than an external video or social service.
Source links take you to other websites with their own privacy policies. If you choose to contribute, payments are handled on Ko-fi, not by this website. Read Ko-fi's privacy policy before providing payment or contact details. If you contact us by email, your email provider and ours handle the message and the information you send.
How long information is kept
Saved preferences and Daily 5 records remain in your browser until you clear the site's data or the stored value is replaced. Temporary animation storage lasts for the browser session.
The Google Analytics retention period is set in the site's analytics account and is not specified in this notice. Hosting and provider retention also depend on their settings and policies. Read Google's privacy policy and Cloudflare's privacy policy, or contact us about retention.
Questions and your choices
Just How Big? is published by Katipo Technologies Ltd (company number 16987462). For a privacy question or a request about personal information, contact the publisher.
Depending on where you live and the information concerned, you may have rights to access, correct or delete personal information, object to its use, or complain to your local data protection authority. Changing analytics consent and clearing browser data are available directly on your device.
Technical details
Local preference keys begin jhb-unit-, jhb-game-settings- and jhb-daily-. Analytics consent is stored as jhb_analytics_consent. The logo animation uses session storage. Typical Google Analytics first-party cookies include _ga and _ga_CEYES2GCDR.
There is no calculation or game-results API. Shared settings use the URL fragment, the part after #. Ordinary HTTP requests do not send that fragment to the server; this does not make it secret from people with the link or scripts running in the browser. Rejecting analytics disables further Google measurement and attempts to remove cookies named _ga or beginning _ga_.
Changes to this notice
Any future analytics or advertising integration should update this notice before it runs and provide the relevant controls.