Image Pixelator - Online Censor & Mosaic Effect Tool

An image pixelator (also known as a mosaic or censor tool) allows you to selectively reduce the resolution of specific areas in a photo by grouping pixels into larger colored blocks. This creates a distinctive "pixelated" or "mosaic" look, commonly used to obscure faces, license plates, sensitive text, or any private information in images before sharing them online. Unlike blurring, pixelation is mathematically straightforward and produces a recognizable 8-bit aesthetic.

No — your image never leaves your device. This tool runs entirely in your browser using HTML5 Canvas and JavaScript. All processing happens locally on your computer or mobile device. We do not upload, store, or transmit your images to any server. This ensures complete privacy and makes the tool safe for handling sensitive or confidential photos. You can use it offline once the page is loaded.

Simply click and drag your mouse (or use your finger on touchscreen devices) directly on the image. A selection rectangle will appear as you drag. When you release, the selected area is instantly pixelated. You can select multiple areas — each one will be processed independently. The tool supports overlapping selections, and you can adjust the pixel block size between selections for varied effects.

The block size controls the intensity of the mosaic effect:
• Small (4-10px): Subtle pixelation, still somewhat recognizable — good for mild obscuring.
• Medium (12-24px): Balanced mosaic effect, good for faces and text.
• Large (28-60px): Heavy pixelation, completely obscures details — ideal for sensitive information.
You can change the block size at any time, even between selecting different areas on the same image.

Yes! The Undo button removes the most recently applied pixelation area, one at a time. The Reset button clears all pixelations and restores the original image instantly. Both operations are non-destructive — your original image data is preserved throughout the editing session, so you can freely experiment without worry.

The tool supports JPG, PNG, WebP, BMP, and most common image formats. After processing, you can download the pixelated image as a PNG file (lossless quality) with a single click. The downloaded image maintains the resolution of the working canvas (up to 1200px on the longest side), ensuring good quality for sharing or printing.

Pixelation (mosaic) replaces groups of pixels with a single averaged color block, creating a distinct grid-like, retro 8-bit appearance. Blurring (Gaussian blur) smooths out pixel transitions, creating a foggy, out-of-focus look. Pixelation is generally more secure for censoring because the original information is mathematically aggregated into blocks, making reconstruction significantly harder than with simple blurring, which can sometimes be partially reversed.

Absolutely! The tool is fully responsive and optimized for touchscreen devices. On mobile, simply tap and drag your finger across the image to select areas for pixelation. All controls — including the block size slider, undo, reset, and download buttons — are easily accessible and sized for mobile interaction. The interface adapts to any screen size.