The PD Journal
Is Our Online PD Tool Private? What Happens to Your Photo
Last updated: October 2026 | Reading time: 5 minutes
Short answer: your photo is analysed in your browser. The site's code does not upload your photo to a server. The page does download the face-detection model files from a public content-delivery network when you start, and that request does not contain your image.
What stays on your device
- The camera frame or the photo you choose to upload.
- The detected face and iris points.
- The measured PD, left/right values and error estimate.
- The PDF report, if you create one: it is generated in your browser.
We have checked the application code that handles the measurement and it contains no upload of the image to our servers.
What your browser downloads
To run face detection locally, the page loads MediaPipe's model and WebAssembly files from cdn.jsdelivr.net. That means jsDelivr, like any host, can see a normal request for those files (your IP address and browser details). Your photo is not part of that request.
What is stored locally
The tool can read one optional number (a personal card-to-pupil depth calibration) from your browser's local storage. Nothing is saved there by default, it is never sent anywhere, and you can clear it from your browser settings.
Practical privacy tips
- Use a private window if you share the device.
- Delete any photo you took for uploading.
- If you share a screenshot of your result, cover the card number.
- Use a card you are comfortable showing the camera: it only needs the card's outline, so a gift or membership card of the same size works as well as a bank card, since the standard size is shared by ID-1 cards.
What we do not know about your device
Browser extensions, screen-recording software and some remote-access tools can see your screen or camera. This is true of any website, so check what is running on your device.