How to blur a video background
Portrait-mode blur for video calls exists, but a clip you already filmed keeps the room in full detail. Here is how to blur it afterward, for free, on your own device.
Why live blur does not help an already-recorded clip
Zoom, Teams and Meet blur the background live during a call using the person's outline detected frame by frame, but that only applies while the call is running; a video already saved to your camera roll, like a selfie clip for a job application or a recording of an old call, has no such option built in.
In a video editor
Premiere Pro and DaVinci Resolve can key out or blur a background using masking and tracking, and do it well, but need a green screen for a clean result, or a lot of manual masking work without one, plus the time to learn a full editor for what might be a single clip.
Mobile apps
Some phone camera apps offer a portrait-mode video option, but only while recording; it cannot be applied afterward to a video shot without it, and the effect is usually locked to that phone's specific camera app rather than any video you drop in.
Blurring an existing video without uploading it
Stayput's video background remover finds the person in each frame with an AI model running in the browser tab, then blurs everything else, fills it with a flat colour, or puts a picture behind them, with no green screen needed and no upload. It can also do the opposite: paint the background solid green so the result can be keyed out properly in a real video editor afterward.
Questions
Can I blur the background of a video I already recorded?
Yes, with a tool that finds the person in each frame after the fact, like Stayput's video background remover, rather than only during a live call.
Do I need a green screen to blur a video background?
No. An AI person-detection model finds the outline of the person without one; a physical green screen is only needed for the cleanest results in a traditional chroma-key workflow.
Does it work with more than one person in frame?
Yes, everyone the model recognizes as a person stays sharp; everything else is treated as background.
Can I put a green background behind someone instead of blurring it?
Yes, Stayput's green screen video option paints a solid green behind the person instead, ready to key out in an editor like Premiere or OBS.