Signal's Face Blur: How It Works, Its Limits, and How to Blur Faces in Any Photo on iPhone

Signal does blur faces, and it does it well, but only for photos you are sending inside Signal. You cannot open the Photos app, pick a picture and run Signal's blur on it, and Signal adds no blur option to the iPhone share sheet. If you want the same automatic face blur for any photo on your iPhone, you need a separate tool. BlurQ, which is our app, does it for free with on-device face detection and lets you choose which faces to hide; other apps and a no-install web tool are covered below.

This guide covers Signal's blur properly first, because it is a good tool and many people searching for it simply want to use it. Then it goes through its limits, the workaround for getting a blurred photo out of Signal, and the ways to blur faces in any photo on an iPhone.

How Signal's Face Blur Works

Signal added a blur tool to its photo editor in June 2020, on both iPhone and Android. According to Signal's announcement, face detection uses the phone's system libraries and all processing happens locally on your device. The tool finds faces for you, and it includes a blur brush because, as Signal says, system face detection does not catch every face.

Here is how to use it. The exact wording of buttons changes between versions, so we describe the general flow.

• Open a chat in Signal and tap the attachment button next to the message field.
• Pick a photo from your library, or take a new one with the camera inside Signal.
• In the photo editor that opens, tap the blur icon in the toolbar.
• Switch on the option that blurs faces. Signal scans the photo on your phone and blurs every face it detects.
• If a face was missed, or you want to hide something else such as a name badge or a license plate, draw over it with the blur brush.
• Tap done and send. The recipient gets the blurred version; the original in your camera roll is not changed.

What Signal's blur does well is easy to list. It is automatic, so a group photo takes one tap. It is private, because detection and blurring happen on the device and the result travels through Signal's end-to-end encryption. It is free and built in. For the job it was built for, hiding people in a photo you are about to send to someone, it is hard to beat.

Where Signal's Blur Falls Short

The limits below are our understanding as of October 2026. Signal updates often, so check the current app before relying on any of them.

• It only works on photos you are sending in Signal. The tool lives in the message composer, not in Photos, so a picture for Instagram or a car listing has to go through a Signal chat first.
• The automatic option is all or nothing. It blurs every face it finds, with no per-face toggle. To hide two strangers and keep your friends clear, you would skip the automatic option and paint each stranger with the brush.
• There is one blur look. You cannot choose between a soft blur, a heavy pixelation or a solid cover, and there is no emoji or sticker option.
• It is for photos. In our understanding, Signal's blur tool does not detect or track faces in videos.
• Nothing is saved unless you send. The blurred image is a message attachment, not a file in your library; getting it out takes the workaround below.
• It is one photo at a time, with the blur redone on each photo you attach.

The Workaround: Blur in Signal, Then Save the Photo

If Signal is already on your phone and you only need a blurred photo once, you can blur it in Signal and then rescue the result from the chat by sending the photo to yourself.

• Open Signal's Note to Self conversation, which is a chat with only you in it.
• Attach the photo, blur the faces as described above, and send it to yourself.
• Open the sent image in the chat and use Signal's save option to put a copy in your Photos library.
• Share that saved copy wherever you need it.

This works, but it is a workaround rather than a feature. It takes several steps per photo. The copy you save is the sent version, which Signal processes for sending, so it may be below the resolution of your original. If disappearing messages are on, the note can vanish before you save it. And the per-face and style limits still apply. Fine for a single photo now and then; if you blur faces regularly, a tool built for it is faster and gives you more control.

Blur Faces in Any Photo on iPhone With a Free App

The disclosure first: BlurQ is our app. It is free on the App Store, runs on iPhone with iOS 18 or later, and does face detection on the device, so nothing is uploaded. Unlike Signal, it works on any photo in your library, lets you choose which faces to hide, and offers several styles. Here is how to blur faces with the BlurQ face blur app for iPhone.

• Open BlurQ and pick a photo from your library. There is no account and no chat to go through.
• BlurQ scans the photo and marks every face it finds. Detection runs on your iPhone and works offline.
• Tap any face to switch its blur on or off. This is the part Signal does not do: hide the strangers and keep your friends clear.
• Pick a style. Gaussian blur, Pixelate and Cover are free. Pro adds seven more, including Mosaic, Hexagon and Bokeh.
• Set the intensity. For people who did not agree to be posted, push it high enough that the face becomes a few flat blocks.
• Use the manual blur brush for anything the detector missed, or for plates, name tags and screens.
• Optionally blur the background as well, which helps with photos taken at home or at work.
• Save. The photo is written at its original resolution to your library, ready to share from any app.

The limits, stated plainly. Free saves carry a small BlurQ watermark; one short ad removes it from a save, and Pro, a one-time purchase of $9.99, removes it for good. Pro also lifts the free video limit of 8 seconds at 720p. BlurQ is iPhone only, with no iPad or Android version, and it does not batch several photos at once. It does handle video: faces are detected and tracked as people move, and you can cover a face with an emoji sticker instead of a blur.

Blur Faces With Nothing to Install

If you do not want another app, you can blur faces online in Safari. Open the page on your iPhone, pick a photo, and the face detection runs inside the browser; nothing is uploaded. You get blur, pixelate and mosaic, an intensity slider and a manual brush, and the result saves to your camera roll with no watermark. It is slower on very large photos and does not handle video, but for a one-off blur it is the quickest route that avoids both a Signal chat and the App Store.

Other Apps Worth Knowing

Three other names come up often when people ask for a Signal blur alternative. We describe them from their App Store listings rather than from hands-on testing.

Redact detects faces and license plates automatically, tracks faces in video with a per-person timeline, and runs on iPhone, iPad and Mac. Single photo exports are free with no watermark; video and batch need Redact Pro at $3.99 a month, $22.99 a year or $59.99 lifetime.

Superblur detects faces, number plates and printed text such as names and addresses, with no watermark on the free version and a $6.99 one-time Pro. The catch is that it requires iOS 27.

Blur Face (photo and video) detects faces, people and backgrounds, with a wide set of cover styles and per-face intensity. Free photos come with a daily limit, and video is Pro only, at $1.99 a week, $12.99 a year or $34.99 lifetime.

We compare these and three more, with privacy labels and two-year costs, in our round-up of the best apps to blur faces.

Signal's Blur Compared With a Dedicated App

Which Blur Actually Hides Someone

Whichever tool you use, the kind of blur matters more than the tool. A light Gaussian blur looks tidy but smears the face rather than destroying it, and research has shown that weak blur can be partially reversed or matched by face recognition. Strong pixelation or a solid cover leaves nothing to reconstruct. Signal applies its blur at a fixed strength; in BlurQ, choose Pixelate or Cover and push the intensity up for strangers and children. Then zoom in; if eyes, nose or mouth still show, go heavier. Our guide to pixelating and censoring faces in photos goes through the trade-offs in detail.

One more check before you post: hair, tattoos, clothing, name tags and reflections in windows or sunglasses can identify someone even with the face hidden, so for strangers it is worth covering a little more than the face.

Wrapping Up

Signal's face blur is a good, private tool for one job: hiding people in a photo you are about to send through Signal. It is not a general photo tool. It blurs all faces or none, offers one look, does not handle video, and only yields a file if you send the photo to yourself and save it from the chat. For any photo on your iPhone, BlurQ gives you the same on-device detection with per-face choice, styles and video, the online tool does it in Safari with nothing to install, and Redact, Superblur and Blur Face each have their own trade-offs. For the wider picture, including Markup without an app, see our guide to blurring faces on iPhone.