Redact a screenshot so it cannot be undone.
Most screenshot "redactions" aren't. A black rectangle drawn in an annotation tool is just a layer sitting on top of the original — anyone with the file can move it aside, delete it, or pull the covered text back out of the format. Arrowbox does it properly: on export, the image is flattened and the pixels under every redaction are destroyed.
Nothing you redact ever leaves your machine. Arrowbox is one self-contained HTML file that makes zero network calls after it loads — the page's Content-Security-Policy (connect-src 'none') blocks them, and an automated build gate enforces it. No account, no sign-up, no watermark, no telemetry. Cut the internet before you paste anything, if you like.
Choose how much to destroy: pixelate, blur, or solid black. It works on any image, not just screenshots — a photo or a scanned letter redacts the same way. Export a flattened PNG, JPEG or PDF at the exact original size, or copy a flattened image straight to the clipboard.
Open Arrowbox — free, no sign-upRuns in your browser. Nothing is uploaded — zero network calls, enforced by the page’s Content-Security-Policy. Desktop browsers work best.
How it works
- Paste your screenshotPress Ctrl+V to paste, or drag-drop the file, or use Open. Any image works, and you can put several on one board and redact them together.
- Pick the Redaction toolChoose a mode: pixelate, blur, or solid black. Pixelate and blur keep some visual context; solid black leaves nothing to guess at.
- Cover the sensitive partsDrag a redaction box over each name, email, key or account number. Be generous with the edges — half a character can be enough to read.
- Export it flattenedPress Ctrl+S and export as PNG, JPEG or PDF. This is where the redaction becomes permanent: the covered pixels are destroyed in the output file, and an untouched image exports at its exact original size.
- Share the export, not the projectThe flattened PNG, JPEG or PDF is safe to send. A saved .json project file keeps the original pixels so you can re-edit — keep that one to yourself.
Why Arrowbox
- Redactions are destroyed on export — the flattened PNG, JPEG or PDF has no hidden layer to recover
- Zero network calls after load, enforced by CSP (connect-src 'none') and an automated build gate — your screenshot never leaves the browser
- No account, no sign-up, no watermark, no telemetry
- Three redaction modes: pixelate, blur, solid black
- Works offline — save the page once (Ctrl+S, "HTML only") and run it from a USB stick or an air-gapped machine
- Free, donation-supported, one self-contained HTML file
Questions
Can the redaction be reversed?
Not from an export. When you export a PNG, JPEG or PDF, the image is flattened and the pixels under each redaction are destroyed — there is no hidden layer or original underneath. The one exception is a saved .json project file, which keeps originals for re-editing. Share exports, not project files.
Is my screenshot uploaded anywhere?
No. Arrowbox makes zero network calls after the page loads. That is not a promise — it is enforced by the page's Content-Security-Policy (connect-src 'none') and checked by an automated build gate. There is no account and no telemetry. Disconnect from the internet entirely and it keeps working.
How do I black out text in a screenshot?
Paste the screenshot with Ctrl+V, pick the Redaction tool, set it to solid black, and drag a box over the text. On export the black is baked into the pixels rather than layered on top, so it cannot be nudged aside or deleted later.
Isn't drawing a black rectangle in an ordinary editor enough?
Often not. In many tools the rectangle is an annotation object sitting above the image — the recipient can move or delete it, and some formats keep the original underneath. Highlighter-style marks can also be semi-transparent. A flattened export removes the question: the covered pixels no longer exist.