How to Blur a Moving Object in a Video
November 3, 2026
Short answerEither draw one box large enough to cover the object's whole path, or chain several smaller boxes with back-to-back time ranges so each one covers the object while it is in that spot. Both work without motion tracking.
Pro editors solve this with motion tracking: you mark the object once and the software follows it. Tracking is great when it works, but it also drifts, loses the object behind obstacles and needs checking frame by frame anyway. For short clips, two manual methods are often faster and more dependable. Blur The Video has no automatic tracking, so these are the methods to use there.
Method 1: one big box
If the object moves within a limited area, such as a person shifting in a chair or a car crossing one lane, draw one box that covers everything it passes through. It is quick and nothing can slip out. The trade-off is that more of the frame is blurred.
Method 2: a chain of boxes
- Open the editor and load your video.
- Go to the first frame where the object appears and draw a box over it, with some margin.
- Click Start here. Play or step forward (arrow keys) until the object is about to leave the box, then click End here.
- Press Cmd/Ctrl + D to duplicate the box. Drag the copy to the object's new position.
- Set the copy's start to the previous box's end (or a fraction earlier, so they overlap), then find its end the same way.
- Repeat until the object leaves the frame or no longer needs hiding. Then scrub through the whole range to check for gaps.
Tips that make it reliable
- Overlap the time ranges by a few tenths of a second. A gap of even one frame is enough for a face to flash through.
- Make boxes generous. A box that is 30–50% bigger than the object can cover it for longer, so you need fewer boxes.
- Fast motion = more boxes. For something crossing the whole frame in a second, a single wide box is usually easier.
- Slow down to check. Set the playback speed to 0.5× while reviewing, then set it back to 1× before exporting, since the speed applies to the export too.
- Pixelate or solid for faces. They read as clearly intentional. See can a blurred video be unblurred for why strength matters.
When this isn't the right tool
For long clips where a person moves constantly, such as a ten-minute walking vlog, chaining boxes becomes tedious. In that case a desktop editor with tracking (DaVinci Resolve, Premiere Pro, Final Cut Pro) will save time, though you should still check the result by hand. For short incident clips, dashcam footage and interviews, the manual approach is usually done in a few minutes and keeps the video on your device.
FAQ
Does Blur The Video have automatic face tracking? No. Boxes stay where you place them. You cover moving objects with a larger box or several boxes with consecutive time ranges.
How many boxes can I add? As many as you need. Each has its own position, effect, strength, start and end time.
How do I avoid a frame where the face is visible? Let each box start slightly before the previous one ends, and make the boxes larger than the object. Then step through the transitions with the arrow keys.
Can I save my work and continue later? Yes. Save a project file, then later load the same video and the project file to get all your boxes back.