Redact phone/ID numbers before sharing
Before sharing a screenshot or ID photo containing a phone number, ID number, or bank card number, paint over those digits with mosaic first to prevent any privacy leak.
Processed locally, never uploaded
Free, no watermark
Paint brush + mosaic/blur modes
Mosaic/Blur Redaction — Paint Over Private Details in Seconds
Redaction style
Redaction intensity
Brush size
Upload an image, choose mosaic or blur, then use your mouse or finger to paint directly over a phone number, ID number, or face you want hidden — the redaction takes effect the moment you paint, undo any mistake and paint again, then download once you're happy. All processed locally in your browser, never uploaded to a server, so private information stays yours.
2redaction styles (mosaic/blur)
20MBmax size per image
0software to install
Never uploaded
Painting and final redaction all happen locally in your browser — the image never passes through any server
Mosaic/blur dual mode
Fully hide text-based info with mosaic, or use blur for a more natural transition on faces and similar content
Precise hand-painted control
Paint directly over the sensitive area with the brush, covering it exactly no matter where it is on the image
Free, no watermark
No sign-up, no payment, and the exported result has no watermark whatsoever
Common Use Cases
Three common privacy-redaction needs, solved by one tool
Whether it's a phone number, an ID number, or a chat screenshot, a quick paint-over lets you share with confidence.
Redact private info in chat screenshots
When forwarding a chat screenshot for help or to share publicly, paint over the other person's avatar, nickname, phone number and other private details, keeping only the conversation content you want to show.
Partially hide details in ID/contract photos
When uploading a photo of a contract, receipt, or ID document, hide a signature, amount, or other text you don't want to reveal, keeping only the part that actually needs explaining.
Compare Effects
When to use mosaic vs. blur
The two effects differ in how completely they hide detail and how they visually transition — picking the right one matters.
| Style | Effect | Best For |
|---|---|---|
| Mosaic | Breaks the painted area into regular, solid-colored blocks, making original text or patterns completely unreadable — the most thorough option | Text-based info like phone numbers, ID numbers, and bank card numbers that need to be fully unrecognizable |
| Blur | Softens the painted area out of focus while keeping a rough outline and tone visible, with no fine detail — a softer, more natural-looking transition | Faces, license plates, and similar cases where you just want to lower recognizability while keeping the overall image looking natural |
Both effects' intensity and brush size can be freely adjusted with the sliders. If you're not sure which to pick, go with mosaic for text-based info, and try blur when redacting a face or anything where you want the image to still look natural.
How to Use
4 steps to mosaic or blur redact an image
No software to install — everything happens right in the browser, painted directly with your brush.
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1
Upload an image
Click to select or drag your image into the page. Supports JPG, PNG, WebP and GIF, up to 20MB, one at a time.
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2
Choose the redaction style
Click mosaic or blur, then drag the intensity and brush size sliders to adjust.
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3
Paint over the area to redact
Use your mouse or finger to paint directly over the sensitive area — undo the last stroke or clear all if you make a mistake.
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4
Download and save
Once every area is properly covered, click download — the effect is baked into the image and saved to your device.
Technical Notes
Two things worth knowing about local redaction
01
Painted strokes and the final export use the same coordinate data
Every stroke's path and brush size is recorded as a proportion of the image's width and height, rather than fixed pixel values — so the redacted area you see in the preview exactly matches the area covered when it's applied to the original-resolution image after download. Downloading redraws the final image using the browser's Canvas drawing API, all done locally on your device without touching any server.
02
Why mosaic/blur doesn't support batch processing
The exact location of the sensitive info varies from image to image — for example, a phone number appears at a completely different spot in each different screenshot — so it has to be painted over by hand in each image's specific location, with no way to apply the same paint coordinates across different images. That's why this tool focuses on careful, single-image redaction — open and paint over multiple images one at a time.
FAQ
Common Questions About Mosaic/Blur Redaction
Does mosaic/blur support batch processing — can I redact many images at once?
No. The sensitive info that needs hiding (phone numbers, ID numbers, faces, etc.) sits in a different spot on every image, and it has to be painted over by hand in each specific location — there's no way to apply the same set of paint coordinates across different images. That's why this tool is designed for careful, single-image redaction. If you need to redact multiple images, open and paint over each one individually.
Is the redaction done on my computer or phone, or does it get uploaded to a server?
It's done entirely in your current device's browser — both the live preview while painting and the final redacted image are generated using the browser's built-in Canvas drawing capability. The original image is never uploaded to any server, which is exactly why this tool is a trustworthy choice for handling private, sensitive information.
Should I choose mosaic or blur? What's the difference?
Mosaic breaks the painted area into blocky, solid-colored tiles, completely obscuring the original detail — it's the more thorough option, ideal for text-based information like phone numbers and ID numbers that need to be fully unreadable. Blur softens the painted area so it's out of focus but keeps a rough outline and color, offering slightly weaker concealment but a more natural-looking transition — better suited for faces or similar cases where you just want to reduce recognizability without making it look artificially blocked out. If you're unsure, go with mosaic for text-based content.
What if I paint over the wrong spot by mistake, or want to adjust the redacted area?
Click “Undo last stroke” to remove your most recent paint stroke — you can click it repeatedly to undo several strokes in a row. If you want to start completely over, click “Clear all” to remove every painted area and return to the unredacted original, then start painting again without affecting the uploaded original. As long as you haven't clicked download, none of these adjustments affect the final result.
What if my brush strokes didn't fully cover the sensitive information?
Increase the brush size slider and paint over that area again, or add a few more strokes to the same spot to widen the coverage — strokes stack naturally, so painting multiple times over the same area builds up the coverage until you can confirm in the preview that the original content is no longer visible, then download.
Will the downloaded image keep its EXIF capture data and PNG transparency?
Redaction essentially redraws and re-encodes the image: PNG's transparency channel is preserved, but if the original has transparent areas and is detected as needing JPG encoding, those areas will be filled with a white background. The original's EXIF capture parameters, location, and other metadata are not preserved after re-encoding — if you need to view or remove EXIF data specifically, use the “EXIF Viewer/Remover” tool.
Upload now and hide private info in seconds
No sign-up, no waiting — download as soon as you're done.