Is blurring a face in a video enough?

By Check Before Send · Updated 13 October 2026

Only if the blur covers the face in every frame, cannot be undone, and the original is not what you send. Blurring is the technique regulators name for hiding people in video, but a blur that moves off the face for a moment, or a face the tool never found, leaves the person identifiable.

This guide sets out what the sources say about blurring, what we measured when we built a face blur, and what to check before you post.

What the sources say

YouTube's help page describes two ways to blur in its editor. Face blur finds faces once processing is complete, and you select which to blur. Custom blur lets you drag a box over any area, and gives a choice between a blur that tracks the object and one that stays fixed. The page notes that changes made in the editor cannot be undone after you save.

The UK Information Commissioner's Office says that techniques for hiding people in footage include blurring, masking, or a solid fill, and that the best one depends on how the footage was made and its quality.

The European Data Protection Board's guidelines on video devices say that blurring a picture with no retroactive ability to recover the personal data it contained counts as erasure under the GDPR. That is a high bar: the blur has to be permanent.

What we measured

We built a face blur for Check Before Send and tested it on real video clips, listed in our own notes. Results from that work:

On three clips with close and medium faces, the detector found a face in every frame we sampled.
On a dashcam clip where people were about 15 to 25 pixels tall, it found someone in 1 sampled frame out of 72. Small faces are a real miss.
On a clip we darkened until its median brightness was under 10, the same people came back as 18 fragments instead of 11 solid tracks. In the dark the detector falls apart.
Between the frames we look at, nothing is seen. The gap is at most 0.4 seconds, so something visible for less time than that can be missed.
The exported video is re-encoded, the covers are burned in and cannot be undone, and the original file is never changed.

For videos you export from our page, we do not run a second scan of the picture for faces or plates afterwards. Watching the result is your check.

What to do

Play the whole exported video, not a few seconds, and watch the faces rather than the scene.
Check the start and end, the edges of the picture, and moments when people turn or move quickly.
Send the exported copy, never the original, and keep the original somewhere private.
Do not rely on any tool in dim light, with distant people, or with faces turned away.

Blur faces in a video on this site

Our video page runs in your browser and does not upload the video; the Trust Center explains how to confirm that. It finds faces, lets you choose which to cover, and exports a new file. Its limits are the ones listed above. For what a video file carries besides the picture, read does a video file carry location and date, or browse the other guides.

Sources

More guides

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