Blur part of a video

What this tool is, and what it is not

This is a redaction tool for short clips. It is built around one job: making something in the frame unreadable before the video leaves your hands. It is deliberately not a video editor, and knowing the boundary up front saves you a wasted upload.

• Not automatic tracking. You place the box. There is no model following a face from frame to frame.
• Not a full editor. No colour grading, no titles, no multi-track audio, no transitions.
• Not a cloud render. Export speed depends on your device. A fast laptop finishes a 60-second clip quickly; an old phone takes a while.
• Not unlimited length. Ninety seconds per export, up to 50 MB, up to 720p.

Handling something that moves

Since there is no tracking, a moving subject needs a plan. There are two approaches and the right one depends on the shot.

One big box. If the thing drifts within a small area, for example a face in a mostly static talking-head recording, make one box large enough to cover everywhere it goes for that whole window. It blurs more of the frame than strictly necessary, and it cannot slip.

Several short blurs in sequence. If the subject crosses the frame, chain shorter blurs: place one, mark it in and out over a second or two, then place the next where the subject has moved to. This keeps more of the picture sharp, at the cost of more work and more chances to leave a gap.

Whichever you pick, scrub the whole clip afterwards at normal speed and watch the target, not the box. A single uncovered frame is enough. Video is unforgiving here in a way stills are not, because a viewer can pause anywhere.

Screen recordings leak more than the thing you meant to hide

Screen captures are the most common clip people need to redact, and they are full of details that are easy to miss while you concentrate on the bug you are demonstrating. Before you export, scrub through looking specifically for:

• Notification banners that appeared mid-recording.
• The browser address bar, which frequently carries tokens, account IDs, and internal hostnames.
• Browser tab titles across the top.
• Autocomplete dropdowns, which surface other people’s email addresses.
• The taskbar or dock, including unread badges and app names you would rather not disclose.

If you are attaching the clip to a ticket, there is a fuller checklist in blurring a video for a support ticket.

Trim before you blur

The fastest way to redact a video is to cut out the part that needed redacting. If the sensitive moment sits at the start while the useful part is the last twenty seconds, trim to those twenty seconds and you may not need a blur box at all. Trimming also makes the export faster, since there are fewer frames to re-encode.

This only works when the secret is at an edge of the timeline. If it is on screen throughout, for example a signed-in account name in a header, you need the box.

Browser support

Chrome and Edge on desktop are the most reliable combination and the most likely to produce an MP4 with audio. Safari and Firefox work but may fall back to WebM or drop the audio track. On phones the editor works, though a long clip on an older device will take noticeably longer to export and can be interrupted if you switch apps mid-render. For anything you actually care about, use a desktop browser.