Pixelate Image — Blocky Mosaic Effect, Free
Pixelate a whole image, or drag to select just one area — a face or license plate.
A free online image pixelator — upload a photo, adjust the block size, and pixelate the entire image or only a selected area. No signup, no quality loss beyond the effect itself. Everything runs in your browser; nothing is uploaded.
What does pixelating an image do?
Pixelating an image replaces small square blocks of pixels with a single averaged color, producing the blocky "mosaic" look often used to obscure a face, license plate, or other sensitive detail. Technically it works by shrinking the image down to a tiny size (so each block of the original blends into one pixel) and then scaling it back up without smoothing — the same trick used to create retro 8-bit style graphics. The larger the block size, the less recognizable the underlying detail becomes.
Pixelating a specific area — censoring a face or plate
Switch to Select area mode and drag a rectangle over the part of the image you want to obscure. Only that region gets pixelated — the rest of the photo stays exactly as it was. This is the common real-world use case: blurring out a face in a screenshot before sharing it, or hiding a license plate, address, or document number in a photo.
Choosing a block size
A small block size (a few pixels) gives a subtle, almost stylistic mosaic that still hints at the original shape. A large block size makes the area genuinely hard to identify — the right choice if the goal is actually obscuring something, not just adding a retro effect. Start around 16px and increase it until the detail you're hiding is no longer recognizable.
A privacy caveat
Pixelation is visually effective for casual sharing, but it isn't cryptographically secure — research has shown that sufficiently light pixelation can sometimes be partially reversed with specialized software, particularly on simple, repetitive patterns like text. For genuinely sensitive material (legal documents, medical records, security footage), use a heavier block size or a solid-color redaction instead of relying on light pixelation alone.
Frequently asked questions
How do I pixelate an image?
Upload, drag, or paste an image. With Whole image mode selected, the entire picture pixelates immediately — adjust the Block size slider to make the blocks bigger or smaller, then click Download PNG.
Can I pixelate just one part of an image, like a face?
Yes. Switch to Select area mode, then drag a rectangle over the part you want to censor — a face, a license plate, a document number. Only that area gets pixelated; the rest of the image stays untouched. Drag again to redraw the area.
What does the block size control?
Block size sets how many source pixels are merged into one solid-colored square. A small block size (a few pixels) gives a subtle mosaic; a large block size gives a heavily blocky, hard-to-recognize result — useful when the goal is genuinely obscuring a detail, not just a stylistic effect.
Is pixelating an image enough to hide sensitive information?
For casual sharing, a large enough block size makes a face or plate unrecognizable to the eye. It is not cryptographically secure — heavy pixelation can sometimes be partially reversed with specialized software. If the information is genuinely sensitive (legal, medical, security-critical), don't rely on pixelation alone.
Is my image uploaded anywhere?
No. The pixelation happens locally in your browser using a canvas — your image never leaves your device, and nothing is stored on a server.
Related tools: Flip Image · Image Fade Effect Generator · PNG Color Replacer · Image Color Picker
