What the mosaic effect hides

Mosaic replaces small pixel blocks with averaged color. Unlike blur, it breaks readable letters and recognizable facial detail into square blocks, which is useful when you need a clearly masked area rather than a subtle retouch.

• Faces, badges, student IDs, name tags, and ID-card fragments
• License plates, shipping labels, receipt numbers, and reservation codes
• Phone numbers, addresses, account fragments, and order identifiers
• Private information reflected in monitors, glass, or background documents

Read the workspace in order

• Add one or more images from the upload canvas.
• When the preview opens, use the toolbar for undo, redo, restore, and PNG download.
• Use the settings strip to adjust block size, brush size, and click/drag mode.
• Check the file queue for name, original dimensions, edit status, and per-file download.

Use click mode for small targets

Click mode applies mosaic around one point. It is best for eyes, a short name, a small number, or one compact label.

• Keep the brush smaller when the surrounding background should stay untouched.
• For tiny text, click more than once with a little overlap.
• Undo immediately if the first point covers too much of the image.

Use drag mode for long lines

Drag mode paints while the pointer or finger is held down. It is for long areas such as a license plate, address line, or list of names.

• Paint along the whole line instead of waiting for a rectangle at release.
• The path changes while you move, so you can see gaps before lifting your finger.
• For sensitive data, drag over the same line twice rather than using one weak pass.

Pick block and brush sizes

Block size controls how coarse the mosaic is. Brush size controls how wide each edit pass is.

Presets are starting points

The Soft, Medium, Strong, and Max buttons only set starting values. A 20 px block can be safe on a small screenshot and too weak on a high-resolution photograph.

• Increase block size for small screenshots or dense text.
• Increase brush width on large photos so edges are not missed.
• Cover a face wider than just the eyes, nose, and mouth.

Supported files and output

• Input: JPG, PNG, WEBP, AVIF, BMP
• Recommended limit: 20 MB per file, 4000×4000 px or smaller
• Output: the current edited canvas is saved as PNG
• Animated GIF is excluded because canvas editing does not preserve animation.

Example workflows

Undo, redo, and restore

The editor keeps a short in-page history while the page stays open. Restore original redraws the currently selected image from the first loaded state.

• A downloaded PNG cannot be un-mosaicked without the original.
• Keep the original photo separately before editing important images.
• When several files are queued, select the file again before continuing edits.

Privacy limits to check

Browser-only processing reduces exposure, but weak mosaic can still leave clues for people or OCR. Cover sensitive areas generously.

• Check glass reflections, monitors in the background, shadows, and badges.
• Small digits often need a larger block or a second pass.
• Open the saved PNG again and inspect it before publishing.

Final check before sharing

• Faces, names, plates, addresses, phone numbers, and order IDs are covered.
• Text is not readable at the mosaic edge.
• The same sensitive area is covered again if the first pass looks weak.
• The saved PNG has been reopened and checked outside the editor.