A cluttered kitchen, a stranger walking past, a shop sign you have no right to show: the background of a clip often carries more than you meant to share. Instead of covering each of those things one at a time, you can mark the part you want to keep and let the tool soften the rest of the frame.
This works with any of the three effects. Blur gives a gentle, out-of-focus look, Pixelate turns the surroundings into a mosaic, and Black box leaves only your chosen shape visible against black. All of it happens in your browser, so the original file stays with you.
Drop the video into the tool above or pick it from your device. Nothing is sent to a server while you work on it.
Switch Apply to from Whole video to Chosen areas. A starter box appears in the middle of the frame: drag it over the person or object to keep, resize it from a corner, and switch it to Oval for a rounder edge.
Pick Blur or Pixelate, then turn on Blur everything except the areas. The switch is worded to match the effect you picked, and the preview updates straight away.
If the subject moves, select Track movement automatically. Set the strength so the background is as soft as you want, then select Export video.
Keeping one thing clear while the rest goes soft is often quicker than hiding many small details, and it suits a few common situations:
Normally the effect goes inside your areas. With the switch on, the tool works the other way round: it applies the effect to the full frame, then paints the original picture back inside each box or oval. Every area you add becomes another window of clear video.
The sharp part is always a plain box or oval. It will not cut neatly around hair, shoulders or a waving hand, so a strip of real background stays visible near the edge of the shape. Fitting the shape snugly to the subject keeps that strip small.
Timing matters more here than usual. While an area is outside its start and end times, nothing is held clear, so the effect covers the whole frame for that stretch. You can use that on purpose to soften an entire scene, or leave the area untimed if your subject is on screen throughout.
The switch applies to every area at once. You cannot keep one person sharp and also pixelate a single face elsewhere in the same export. For that, export the first result, open the new file, and make the second change in another pass.
A presenter who stays in one spot needs nothing more than a single fixed shape. If the subject walks or leans, or the camera pans, the clear window has to move as well, or the person drifts into the blurred part.
Select the area and choose Track movement automatically. The tracker follows the look of whatever sits inside the shape, both forwards and backwards from the playhead, and saves the positions it finds so you can adjust any of them. A shape around a head and shoulders tends to hold better than one around a whole body, since arms and legs change shape as someone moves.
To keep every person sharp, select Find faces automatically first and then turn on the switch. Each detected face stays clear while that person is in shot, and the rest of the frame is blurred. When nobody is in shot, the whole picture is blurred. The face blurring guide explains how detection works.
For a soft, cinematic look, a moderate Blur amount is often enough, because the aim is to tone detail down rather than destroy it. If the background holds something that must not be read, such as a whiteboard, a screen or a document, push the slider much higher or use Pixelate with big blocks.
Strength is set in pixels of the original video, so a 4K clip needs a higher number than a 720p clip to look equally soft. Judge it at full screen before you export.
Black box in this mode turns the surroundings solid black, leaving only your shapes visible. It suits a spotlight effect, or a clip where nothing but the subject may be shown.
Choose Blur and Chosen areas, move the box over the person, then turn on Blur everything except the areas. If they move, select Track movement automatically. Select Export video when the preview looks right.
It does not. The clear part is a box or oval you place, not an outline traced around the body. Fit the shape closely, and choose Oval for a head and shoulders, to keep the leftover background small.
Yes, add an area for each person, or use Find faces automatically to make one per face. Every area stays clear while the rest of the frame is softened.
An area only keeps its part clear between its start and end times, and outside them there is nothing to hold sharp. Select the area and remove its times with the X beside them, or set them to match when the subject is visible.
Pick Pixelate and the switch becomes Pixelate everything except the areas. Black box behaves the same way and leaves only your shapes showing.
The clear area shows the original frame, encoded along with the rest of the video at a high bitrate. A smaller size or file under Export settings trades some of that quality for a lighter download.
Tracking, face finding and the background effect all run in your browser. The finished clip is written straight to your device.