Why this page starts calm
This page and the Amazon Appstore promo page run the same builder, but they open on different defaults, and the difference matters more than it sounds. Here the motion is Slow zoom and the transition is Fade. On the Amazon page it is Zoom and pan with Slide.
Slow zoom moves the frame by about 8% over the life of a slide. That is enough to stop the shot feeling like a static screenshot and little enough that a list of settings, a feed, or a form stays legible while it moves. A harder pan on a text-dense Android screen makes the viewer work, and they usually do not.
Both defaults are just starting points. Every control stays available, so you can switch to Zoom and pan, to Cut transitions, or to Still if the screenshots already carry the message on their own.
Building the sequence
Add 2 to 8 screenshots as PNG, JPG, WebP, GIF, or BMP files of up to 12 MB each. Each becomes one segment and the chosen length is divided evenly between them, so fewer screens means longer on screen for each. Move earlier and Move later reorder them, Replace swaps an image while keeping the framing, and Remove drops one.
Per-screen framing is a zoom slider from 0.55 to 1.7 plus horizontal and vertical offsets. This is how you fit a tall phone screenshot into a square or landscape canvas without stretching it. A background color picker fills whatever the screenshot does not cover, so the letterboxing can match your app rather than sitting on a default gray.
The canvas presets are 1080 by 1920, 1080 by 1080, 1920 by 1080, App Store 886 by 1920, App Store 1920 by 886, Google Play 1080 by 1920, and Google Play 1920 by 1080. Lengths are 6, 10, or 15 seconds. Everything renders at 30 frames per second.
- Add and reorder 2 to 8 screenshots
- Frame each one with zoom and offsets
- Pick a canvas preset and a length
- Optionally add a headline, badge, and closing card
Text overlays and how the file is encoded
Three optional text fields live behind the advanced toggle and all start empty. The headline takes up to 42 characters, renders white over a dark gradient across the top of the frame, and wraps to a maximum of two lines. The badge takes up to 18 characters and draws as a small purple pill. The closing card takes up to 28 characters and adds an extra segment at the end, which shortens the time given to each screenshot.
Frames are drawn on a 2D canvas by the same code that drives the live preview, then encoded by the best available route: the browser video encoder producing H.264 in MP4, or ffmpeg compiled to WebAssembly producing MP4 if that is not available, or a WebM recording as a last resort. The WebAssembly route pulls its core down on first use and runs slower. There is no audio track on any of them.
No screenshot leaves the browser at any point. The only outbound request during an export is a usage counter carrying the tool name, and the export will not start if it fails, so this is not an offline tool even though the rendering is local.