Four phones on the café table, face down. Somebody's buzzed, we all flipped ours over, and three of the four woke up to the same wallpaper. The one that came with the phone. Mine was one of the three.
I have had this phone for more than a year and never changed the lock screen. But a wallpaper stops being yours the moment you see it on two other phones at once.
What I wanted was easy to say and oddly hard to get: a lock screen that moves, that nobody else has, with nothing to pay and no new account. Store live wallpapers are shared with everyone who installed the same one, stock clips with everyone who searched the same word. The only way to get one nobody else has is to describe it yourself.
What the phone can already do
Galaxy phones take a video on the lock screen with no extra app. Samsung's own support page spells it out: touch and hold the lock screen, unlock as usual, tap Wallpapers, then Gallery, pick a video, tap Done, with a Trim slider at the bottom if the clip is too long. The same page gives a home screen route through Wallpaper and style, Change wallpapers, Gallery.
On a Pixel it is a different story. Google's help page on changing wallpaper covers your own photos, preset pictures and a daily rotation, and never mentions a video. For a Pixel and most other brands the usual route is a video wallpaper app from Google Play. Search for video live wallpaper and you get a page of them, none of the top ones showing a price, and they all do the same job: pick a clip from your gallery and set it as the lock screen, the home screen or both.
Describing the thing
rewind.ai's video page is a plain form with no gate in front of it. Two parts matter for a wallpaper: the text box where the scene goes, and the aspect menu under it, which has to say Portrait or the phone crops a wide clip in half.
I typed: gentle waves washing over black sand at night under bright moonlight, white foam spreading and pulling back, top-down view. Water from above, because a lock screen should be easy to look at for a second. Black sand and night, so the time would sit on something dark. No people, no boats, no horizon; the clock and the notifications already own the top half of the screen.
My sentence in the box, with the aspect switched to Portrait before I touched anything else.
Pressing Generate brought up one question, an email address, and nothing else: no password, no card. Then the clip appeared in a tall phone-shaped player, a line above it saying it was done, a green download button beneath and a second one that copies a link.
The finished waves; the green button saves the MP4 to the phone.
The clip is the scene seen straight down, like a drone hanging over a beach at night. A strip of dark shore runs up the left edge, a line of white foam curves across deep blue water and pushes over the sand, and as it plays the foam spreads into a wide bright band across the frame, lacy over green-blue water. Three seconds is what the free run gives you, and a lock screen is on for about that long anyway.
Where the wave begins and where it ends: a curve on the shore, then a band across the screen.
If you want your own, the Rewind AI video generator is where mine came from: type the scene, switch the aspect to Portrait, answer the email question when Generate asks it, and download on the phone itself so the file lands in your gallery.
Everything else I tried that evening
Gemini first, because it is already on the phone. Logged out you get a chat box and a Sign in button in every corner. I asked for the same waves as a short video; it said it was getting too many requests to do that, and a card slid in under the reply inviting me to sign in for Google apps, image making and the rest. Google Flow's Create button goes straight to the Google account page.
Meta AI puts a sign-in card over its question box before you can type a word; the box is useless until you log in or sign up.
Kling's home page is a film trailer with a Try Now button. Pick the text-to-video tool and a welcome box drops over it, with Google, Apple or an email address as the only ways in.
Kling: the welcome box comes before anything else.
Pexels is the stock route and asks for nothing. Search videos for ocean waves aerial, set the filter to Vertical, hover a card and a Download button appears on it. A sponsored column from a paid library sits on the right, clearly labelled. The catch is the one I started with: the top results are on every meditation app and every phone that searched the same words. Pixabay never let me in; it wanted a box ticked to prove I am not a robot.
Somebody else's waves, free to take: download on the card, paid ones off to the side.
| Where | Before the first clip | What I got | Suits |
| rewind.ai | An email at Generate | My waves, portrait, as an MP4 | A wallpaper only on your phone |
| Gemini | Google sign-in for video | A busy message and a sign-in card | People in a Google account |
| Meta AI | Log in or sign up first | A sign-in card over the box | People inside Meta's apps |
| Kling | Google, Apple or email first | A welcome box | People who make video every week |
| Pexels | Nothing | Real drone footage, free download | When any waves will do |
Putting it on the lock screen
On a Galaxy it is a minute of tapping.
- Download the MP4 on the phone, or send it to yourself. It shows up in Gallery.
- Touch and hold the lock screen and unlock the way you normally do.
- Tap Wallpapers, then Gallery, and pick the clip.
- Tap Done. To shorten it, tap Trim, drag the slider, and tap Play to preview.
- Tap Done at the bottom, then Done in the top right.
For the home screen: touch and hold a home screen, Wallpaper and style, Change wallpapers, Gallery, then the same Trim and Done. I left mine alone; icons over moving water looked busy. On a Pixel or another brand, install a video wallpaper app from Play, pick the clip, apply it.
What to put in the box, for a lock screen in particular
- Leave room for the clock. Ask for a quiet patch: dark sand, deep water, plain sky. The phone puts the time on top of whatever you make.
- Portrait, every time. No faces, no hands, no lettering; that is where generated clips go strange.
- Ask for motion that looks fine starting over: water, rain, smoke, snow. A wave that resets still reads as a wave; a car that resets reads as a glitch.
- Keep the camera still; a top-down view with no move is why mine sits quietly under the clock.
The next time the four phones were on the table, mine woke up to black sand and moving foam, and the person opposite asked which app it was from. It is not from an app. I made it up and typed it in. Then she asked for the sentence, which I suppose means it will be on two phones by next week.
