You're in a group chat and want to share a funny screenshot — but your friend's avatar and phone number are right there. You need to send your ID card to customer service, but the address and ID number are visible. You're writing a tutorial and need to blur out sensitive information in screenshots.
Mosaic (pixelation) is the most common way to protect privacy in images. But here's what most people don't realize — a poorly applied mosaic is no protection at all.
Using Mosaic the Right Way
When should you use mosaic?
- Chat screenshots — Hide avatars, nicknames, and phone numbers
- ID documents — Obscure ID numbers, addresses, and expiration dates
- Bank statements / payment screenshots — Block account balances and transaction IDs
- Work emails / document screenshots — Cover sensitive business information
Mosaic vs. solid-color blocking — which is better?
| Method | Best for | Risk |
|---|---|---|
| Mosaic / Pixelation | Less sensitive info, looks natural | Small pixel blocks can be partially restored |
| Solid-color blocking (black/white bar) | Critical info (ID numbers, passwords) | Completely opaque, impossible to restore |
Rule of thumb: Use solid-color blocks for truly sensitive information (ID numbers, passwords, addresses) and mosaic for less critical items like avatars and usernames.
Step-by-Step: Mosaic with PixelForge
Open the PixelForge mosaic tool and follow these steps:
Step 1: Upload your image Drag and drop the image you want to process. Everything is handled locally in your browser — your image never leaves your device.
Step 2: Adjust the pixel block size Use the slider to choose your pixel block size:
| Size | Range | Best for |
|---|---|---|
| Small | 5–10 px | Fine-grained masking, small areas |
| Medium | 15–25 px | Standard blocking, chat screenshots |
| Large | 30+ px | Heavy blocking, ID numbers and critical info |
Step 3: Download the processed image Once you're satisfied, download the result. No uploads, no servers, no data leaks — your privacy is protected twice over.
Pro Tips
- Multi-region masking — If your image has multiple areas that need blurring, you can process them one by one on the same image
- Chat screenshot stitching — Use the image stitching tool to combine multiple chat screenshots into a long image first, then apply mosaic in one go
- Batch processing — Need to blur multiple screenshots at once? Process them all together for efficiency