Swap Blocks of Pixels in JPG
Scramble a JPG by swapping rectangular pixel blocks. Runs entirely in your browser, so your data never leaves your device.
Drop a file here, or click to browse
Files never leave your device
Output
The result appears here as you type.
How to use Swap Blocks of Pixels in JPG
- 1. Upload your JPG. Drop the photo you want to scramble into the input pane. The tool divides it into rectangular blocks that will be shuffled in pairs.
- 2. Set the block size. Enter Block size (px), such as 16, to control how large each swappable square is. Smaller blocks give a finer scramble, larger blocks create bigger, more visible chunks.
- 3. Set the number of swaps. Enter Number of swaps, such as 20, to control how many block pairs get exchanged. More swaps disturb a larger portion of the image, fewer swaps leave more of it recognizable.
- 4. Download the scrambled JPG. Click process and download the result. At the example settings, 20 pairs of 16x16 blocks are exchanged, giving a puzzle-piece look to the photo.
When to use Swap Blocks of Pixels in JPG
Swap Blocks of Pixels in JPG scrambles a photo by exchanging rectangular blocks rather than individual pixels, giving a chunkier, more structured jumble. It suits situations where a puzzle-like or tiled disruption is wanted instead of fine grain noise.
- Puzzle-style visual effects. A design or game asset needs a shuffled, jigsaw-like version of a photo, and swapping 16x16 blocks gives a chunky, tile-shuffled look distinct from a smooth glitch effect.
- Partially scrambling without full noise. You want to disturb a photo enough that details are hard to make out at a glance, but keep recognizable color regions intact, which block swapping preserves better than pixel-level swaps.
- Testing block-based image algorithms. You are testing a codec or algorithm that operates on fixed-size blocks, and a photo with known blocks swapped is a useful input for checking how the algorithm handles disrupted block boundaries.
Examples
Shuffle 16×16 blocks
Input
photo.jpg + block size 16 + 20 swaps
Output
photo.jpg with 20 pairs of 16×16 blocks exchanged
About the Swap Blocks of Pixels in JPG tool
Swap Blocks of Pixels in JPG runs as plain JavaScript in your browser tab, with no server behind it. Scramble a JPG by swapping rectangular pixel blocks. Whatever you put in stays on your device from start to finish.
The tool is part of EditSafely's JPG Tools section, 145 single-purpose utilities built around the same idea: open the page, get the result, keep your data to yourself.
You can shape the output with 2 settings, including Block size (px) and Number of swaps, and the result refreshes the moment you change one. The finished file is put together in browser memory and saved with the Download button, so it never touches a server on the way to your disk. A worked example further down the page shows exactly what the tool produces for a real input.
That local-first design has practical benefits beyond privacy. The tool keeps working on a flaky connection once the page has loaded, results are instant because nothing round-trips to a server, and it is safe to use with confidential material.
Frequently asked questions
Is Swap Blocks of Pixels in JPG free to use?
Yes, it is completely free. All 2,658 tools on EditSafely work without an account, a subscription or usage limits.
Are my files uploaded to a server?
Everything happens locally. Your browser downloads the tool's code once, then does all the processing itself; nothing you enter is transmitted, stored or logged. You can even go offline after the page loads and it will still work.
Which files does Swap Blocks of Pixels in JPG accept?
It accepts JPG and JPEG photos. There is no file size cap imposed by a server; very large files are limited only by your device's memory.
Do I need to sign up or install anything?
No. The tool works in any modern browser on desktop, tablet or phone. There is no account to create, no extension to add and no software to install.
How do I save the output?
Click the Download button once the result is ready. The file is built in your browser's memory and handed straight to your downloads folder, without passing through a server.