Privacy Policy

1. Who we are

Hidden3DImage ("we", "us") operates the website at hidden3dimage.com, a free browser-based tool for creating autostereogram images, together with related educational content. For privacy questions, contact [email protected].

2. What happens when you use the generator

All stereogram generation is performed locally in your web browser using the HTML5 Canvas API. Specifically:

• text you enter is processed only in your browser's memory and is never transmitted to our servers or any third party;
• depth maps and generated stereogram images are created and held only on your device;
• downloading a PNG uses your browser's built-in canvas export — no file passes through a server;
• the analytics described in section 5 measures page visits only — your text, depth maps, and generated images are never sent to it, or to us, or to anyone else.

In short: we can measure that someone visited the generator page, but we cannot see, store, or recover anything you create with it.

3. Server logs

Like virtually all websites, our static hosting provider automatically records standard technical logs when pages and assets are requested: IP address, date and time, requested URL, referrer, and browser user-agent string. These logs are used for security, abuse prevention, and aggregate traffic statistics, and are retained only as long as the hosting provider's standard policy requires. They never contain generator inputs or outputs, because those never leave your device.

4. Cookies and similar technologies

Hidden3DImage does not set any cookies of its own, and does not use browser local storage — your generator settings are not persisted between visits. However, the analytics service described in section 5 does set cookies in your browser.

Cookies currently in use:

• _ga — set by Google Analytics to distinguish one visitor from another. Typical lifetime: up to 2 years.
• _ga_<container-id> — set by Google Analytics to maintain session state. Typical lifetime: up to 2 years.

You can block or delete these cookies at any time through your browser's cookie settings. Blocking cookies does not stop Google Analytics from running — it only prevents your visits from being linked together across sessions. To stop Analytics data collection in your browser, install Google's official Analytics opt-out browser add-on. Private or incognito windows may limit Analytics tracking depending on your browser and its settings; some browsers block third-party requests or discard cookies automatically, while others may still allow measurement. None of this affects the generator: every feature of this site works normally without cookies.

5. Third-party services

Google Analytics 4. We use Google Analytics to understand which pages visitors find useful and how they arrive at the site, so we can improve the content. It collects standard measurement data such as pages viewed, approximate location derived from IP address (city-level, not precise), device and browser type, referring website, and general interaction events. We use it only in aggregate — we do not attempt to identify individual visitors, and we never send your generator inputs to it. Google processes this data as described in its privacy policy; see also how Google uses data when you use our partners' sites or apps.

Google Fonts. Pages load the IBM Plex Sans and Outfit typefaces from Google Fonts. When your browser requests these font files, Google receives standard request data such as your IP address and user-agent.

Advertising. The site currently displays no advertising and sets no advertising cookies. We intend to apply to Google AdSense to help cover hosting costs. If and when advertising is introduced, third-party vendors including Google may use cookies or similar technologies to serve ads based on your prior visits to this or other websites, and Google's use of advertising cookies enables it and its partners to serve ads to you based on your visit to this and other sites. You will be able to opt out of personalized advertising through Google Ads Settings, and to opt out of third-party vendor cookies via www.aboutads.info/choices. Where required by law — including for visitors in the European Economic Area, the United Kingdom, and Switzerland — we will add a consent management mechanism before any advertising or non-essential cookies are set. We do not currently operate such a mechanism; this policy will be updated with the specific details before any ads appear on the site.

6. Children

The site is a general-audience creative tool and is not directed at children. We do not knowingly collect personal information from children, and we do not ask any visitor for their name, age, or contact details. If you believe a child has provided us with personal information through an email to us, please contact us and we will delete it.

7. Legal basis and your rights

Where the GDPR or similar laws apply, our legal basis for the limited processing described above is our legitimate interest in operating, securing, and improving the site — and, where required for non-essential cookies, your consent. Depending on where you live, you may have rights to access, correct, delete, or restrict the processing of personal data, to object to processing, or to lodge a complaint with your local data protection authority.

Because we do not operate accounts, do not run forms that submit data to our servers, and never receive your generator inputs, we normally hold no personal data that would let us identify you. Analytics data is aggregated and held by Google under its own retention settings, and hosting logs are held by our provider. You are welcome to contact us at [email protected] with any request or question, and we will respond.

8. Changes to this policy

If our practices change — for example, if we add advertising or analytics — we will revise this page and update the "last updated" date above. Material changes will be noted clearly on this page.