Blur Sensitive Information

Pixelation vs blur vs cropping

This tool pixelates: it replaces each selected area with large blocks of averaged colour, and the original detail is overwritten in the saved file rather than hidden under a layer. The block size scales with the selection — roughly eight blocks across its shorter side, and never smaller than six pixels — so each block swallows several characters' worth of detail.

No redaction method is equally strong for everything. Research tools such as Depix have shown that pixelated text can sometimes be reconstructed when the blocks are small and the font is known, and a light blur can leak even more. For the highest-stakes strings — passwords, recovery codes, API keys, full card numbers — don't just obscure them: crop them out of the image entirely.

A checklist before you share a screenshot

• Names and profile pictures of other people in chats, comments or email threads.
• Email addresses, phone numbers and usernames — including your own, in the corner of the app you're capturing.
• Order, booking, tracking and account numbers.
• Barcodes and QR codes: a boarding-pass barcode contains your name and booking reference, which can be enough to open the booking.
• Browser tabs, bookmarks and notification banners at the edges of the screen.
• Reflections in glasses, windows and screens in photos.

Why redacting in the browser is the safer choice

The images people redact are, by definition, the ones they don't want anyone else to see. Many online editors upload the file to a server to process it, so the unredacted version exists somewhere else, at least briefly. Here the drawing happens on a canvas in your own browser tab, and the only copy that ever leaves your device is the one you choose to share.

One more trap: some phone markup tools draw a semi-transparent highlighter rather than an opaque mark, and adjusting brightness can bring the text back. Pixelation writes new pixel values, so there's nothing underneath to recover.