How do you set this as your lock screen?
Export the PNG, then open Photos and find it. Tap Share, choose Use as Wallpaper, then Set. If you exported the paired home screen too, choose Set as Wallpaper Pair and pick each one when prompted.
On Android: open the saved image, tap the menu, and choose Set as wallpaper.
Do your photos get uploaded?
No. There is no upload endpoint on this page and no request carrying image data. Photos are decoded, shrunk and drawn entirely inside your browser, and the PNG is generated on your device.
You do not have to take our word for it: open your browser's developer tools, go to the network tab, and add a photo. Nothing appears.
Why do the guides matter?
An iPhone lock screen puts the clock across the upper third, a date line above it, widgets beneath, and a torch and camera button in the bottom corners. A collage designed without knowing that ends up with someone's face behind the clock.
The dashed boxes show where those live. They are drawn on the preview only and never appear in the exported file.
Is there a watermark?
Only if you tick the box, and it is off by default. A board about your own life should not carry someone else's logo unless you decided you wanted it there.
Does it work offline?
After the first visit, yes. The page caches itself so you can come back and build a board with no connection at all — which also happens to be the clearest possible proof that nothing is being sent anywhere.