Image Mosaic & Blur — Hide Faces or Plates Before Posting (Free, No Upload)
Drag-select any area of an image and apply a mosaic (pixelation) or blur effect. Perfect for hiding faces or license plates before sharing photos on social media. Processing happens entirely in your browser; images are never uploaded to a server.
What pixelating and blurring an image does
Before putting a photograph online there is often something you would rather hide: a stranger's face caught in the background, a car's number plate, text on a document. Load an image here and **simply drag over what you want hidden to apply a pixelation or a blur**. You can drag as many times as you like on the same image, treating several areas in turn, and an undo is provided.
**All processing happens inside your browser; the image is never sent to a server.** For a tool whose whole purpose is handling images that contain something sensitive, that is not a point worth compromising on. Note that either mode produces **an irreversible change that the original cannot be recovered from** — though if the block size or blur radius is too small, what lies beneath may still be legible, so apply it generously when hiding text or a number plate. PNG, JPG and WebP are supported.
How to treat an image
- Load the image Drag and drop it, or click to choose a file.
- Choose the mode Select either pixelation or blur.
- Adjust the strength Set the block size for pixelation, or the radius for blur. **Go strong when what you are hiding is text.**
- Drag over what you want hidden Dragging across the image applies the treatment to that area straight away.
- Repeat as needed, then save Work through each area in turn and download the finished image at the end.
Tips for getting more out of it
- You can adjust the block size (mosaic) or blur strength with the slider before dragging. Larger values make the original content harder to make out, so choose a larger value if you need to hide something reliably.
- To hide several faces or license plates in the same photo, just drag over each area one by one — every drag is applied immediately, so you can repeat as many times as needed.
- The "Undo" button removes every mosaic or blur applied so far and restores the original image, which is handy if you selected the wrong area.
- Downloaded images are always saved as PNG, so any transparency in the original is preserved in the result.
- The selection area is always processed against the image's original resolution, not its on-screen display size, so accuracy is unaffected even when the preview is scaled down.
Where this helps
Checking a photo before posting it
Hide a stranger's face caught in the background, or a nameplate that would identify where you live.
Sharing photographs of a car
For listing photos when selling, you can obscure the number plate before publishing.
Sharing a screenshot of a document
Black out only the parts you would rather not share — a name, an address, an account number.
Preparing a screenshot for a bug report
Remove the personal information visible on screen before sending it to a development team.
Image treatment terms explained
- Pixelation
- Dividing the area into a grid of blocks and filling each block with its average colour.
- Blur
- Mixing each pixel with its neighbours so that edges dissolve. It reads more naturally than pixelation.
- Block size
- The coarseness of the pixelation. **Too small and the original text may still be legible.**
- Irreversible treatment
- A change that cannot be undone. **Unlike a solid fill, a light pixelation leaves room for someone to attempt recovery, so apply it generously.**
- Exif
- The capture information embedded in a photograph. It can include location data, which survives separately even after the visible image is treated.
- Client-side processing
- Work done entirely within the browser. **It means the image never leaves your device.**
Frequently Asked Questions
Side Note — Which hides better, mosaic or blur?
The pixelated mosaic used to cover faces on Japanese television is actually a broadcasting-industry convention rather than a legal requirement. Overseas news footage more often uses a soft "blur" effect for the same purpose, and this difference is often attributed to varying broadcasting cultures and audience expectations across countries.
Technically, mosaic (pixelation) is a simple process that averages the colors within a region and replaces them with uniform blocks — and precisely because it is so simple, it makes it visually obvious at a glance that information has been removed. Blur, on the other hand, blends neighboring pixels together with weighted averaging, producing softer edges that look less jarring, but it tends to give less of the "this can absolutely not be read" confidence that a large mosaic block size provides.
There have been research reports and real-world cases of recovering the original license plate numbers or text from images with weak mosaic or blur applied. If the block size or blur radius is too small, comparing multiple processed images or inferring from surrounding context can sometimes reveal the original content, so anything you genuinely want to hide should use a larger block size or stronger blur.