Reels and Shorts Safe Zone Guide — see what the interface covers
A vertical video is never shown bare. The app paints its own interface over the frame — a caption block along the bottom, a column of action buttons down one side, a progress bar, a header — and whatever sits underneath that chrome is invisible on the live post. The editor you exported from showed you a clean 9:16 rectangle, so a title that looked centred and a logo that looked clear of everything are only discovered to be half-covered once the post is public. This safe zone guide draws the covered regions over a frame you supply — a cover image, a thumbnail, a keyframe screenshot — so you can see what survives before you publish. Your image is processed entirely in your browser and is never uploaded.
The safe box, and why it shrinks with every platform you add
Each platform covers a different set of rectangles. Select one and the outline shows what that app leaves alone. Select three and the tool draws the union of everything they cover, which is the intersection of their safe boxes: the area that clears all of them at once. That box is always smaller than any single platform’s, and usually smaller than people expect, which is the whole argument for looking at it rather than guessing. The readout under the frame gives the box as a share of frame area and as a pixel rectangle at 1080 × 1920, so you have a number to type into an editor.
The bar strip underneath shows one row per selected platform and four segments per row — top, right, bottom, left. It answers the question a combined number cannot: which platform is the reason your title has to move. Three apps can agree on every edge except the bottom, where one of them takes twice as much as the others, and that single row is the constraint you are actually designing around.
Percentages of the frame, not pixels
Every inset here is stored as a fraction of frame width or height. Platform interfaces scale with the viewport: an action rail measured as 120 px on one handset is a different number of pixels on a larger phone, on a tablet and in a desktop browser, so a pixel figure is correct on exactly one device and wrong everywhere else. Fractions survive the rescale, and the tool converts them to pixels only at the moment it draws or reports.
Images that are not 9:16
A square or landscape source is still drawn: it is scaled to fit, centred, and the empty bars are marked as outside the frame. Nothing is stretched and nothing is cropped, because a silently stretched preview would answer a question you did not ask. Seeing how little of a vertical frame a 16:9 still can fill is usually the more useful result — it says the picture needs re-framing before safe zones matter at all.
Exporting the overlay
Two downloads are offered. The annotated preview flattens your image and the overlay into one file, which is what you send to whoever asked why the caption was covering the price. The overlay on its own is a transparent PNG you can drop onto a layer in your own editor and design against directly; it is always PNG, because JPEG has no alpha channel and would fill every transparent pixel with an opaque colour.
What this tool does not do
It does not crop, resize, split or re-encode your video or your image — it produces exactly one annotated frame. It has no field for an image address, because a cross-origin image taints the canvas and breaks the export. And it makes no claim about views, reach or engagement: which pixels an interface covers is checkable, and what that does to a post is not.