Blur or redact private details in any image
Need to hide a face, a license plate, an email address or an account number before sharing a screenshot? This tool lets you draw boxes over any image and either blur or black them out. Because it runs entirely in your browser, it is safe for IDs, invoices, bank statements and other private documents.
How it works
The image is drawn onto an HTML <canvas> at its true pixel size. When you drag
a rectangle, the tool records its coordinates. For each box it then either:
- Black box: fills the rectangle with a solid black
fillRect, removing all detail. - Blur: clips to the rectangle, sets
ctx.filter = blur(Npx)(radius from the slider, default 16px), and redraws the image so only that region is softened.
All boxes are baked into the pixels, so the saved file has no recoverable original detail.
When to use blur vs. black box
Choosing the wrong mode is the most common mistake:
| Mode | Effect | When to use it |
|---|---|---|
| Blur | Softens pixels; layout visible | Faces, license plates where some context helps |
| Black box | Completely opaque fill | Account numbers, SSNs, passwords, addresses |
For anything security-critical — account numbers, national IDs, passwords, signatures — use Black box. A blurred image retains pixel data that can sometimes be partially recovered with image-processing techniques; a solid fill rectangle has nothing underneath it in the exported file.
Common use cases
- Job applicant documents: blur the photo and address before sharing with interviewers; keep the qualifications visible.
- Screenshots for bug reports: black-box any session tokens, API keys, or customer data before filing a ticket.
- Social media posts: blur faces in crowd photos where you did not get consent from everyone in frame.
- Invoice or receipt sharing: black-box account numbers and personal details before forwarding to a third party.
- Scanned IDs: black-box the document number, date of birth, or address when only the name needs to be visible.
Example walkthrough
You need to share a bank statement with a landlord to prove income, but you want to hide all transaction descriptions and the account number at the top.
- Drop the statement PNG onto the tool.
- Choose Black box. Drag a rectangle over the account number. It disappears behind a solid black fill.
- Switch to Blur (radius 20px). Drag rectangles over each individual transaction description, leaving the total balance line visible.
- Click Export PNG. The downloaded file has the redactions baked in — there is no hidden layer or metadata revealing the original values.
Why “baked in” matters
Redaction tools that work with layers (like graphic design apps) still store the original content in a hidden layer unless you explicitly flatten the file. This tool applies the redaction directly to canvas pixel data before the image is exported, so there is genuinely nothing beneath the black boxes in the saved PNG. There is also no server involved — your document never leaves your device.