Practical workflow and result checks

Separate covering pixels from making a visual effect

Image Redactor draws flattened layers onto a local screenshot or raster photograph. It offers an opaque covering rectangle, blur, pixelation, arrows and text annotations, together with undo and redo. Use opaque covering for information you need absent from the exported pixels. Blur and pixelation are visual effects: they can leave words, faces and contextual clues recognizable and are not assurances of safe redaction. The page exports a new PNG rather than an editable layer document. It does not redact PDFs, search for secrets automatically or check every part of an image. Review the complete result yourself before allowing anyone else to receive it.

Worked example: cover a fictional dispatch reference

Make a 100 by 60 pixel test screenshot with a fictional dispatch reference near its center. Upload the PNG, keep the covering-rectangle tool active and drag a rectangle fully over the reference with some margin. The default cover color is red; choose black if that is the convention for your document. Download the PNG and reopen it. Pixels inside the selected rectangle should contain the opaque covering color, while areas outside it should retain their original appearance. Undo removes the most recent layer in the editor; Redo restores it. Those actions do not alter a PNG already downloaded, so save a fresh result after changing a layer.

Select enough area and inspect the boundary

The drawing coordinates are mapped from the displayed canvas to the original raster dimensions. A rectangle dragged from right to left is normalized to the same positive area as one dragged in the other direction. Allow space around letters, shadows, antialiasing and nearby labels that reveal the concealed value. A tiny drag does not create a useful rectangle. On a touch device, use the canvas gesture carefully and inspect the resulting region before saving. A visual crop, a browser zoom change and the original pixel dimensions are different things. The exported image keeps the source dimensions rather than exporting only the selected rectangle.

Layers, annotations and reversible editing

Each committed drawing operation adds a layer in the current session. Undo removes the latest operation, and a new operation after undo starts a new history branch instead of preserving an obsolete redo sequence. Arrows identify locations without concealing them. Text annotations are drawn with a contrasting backing and become raster pixels in the exported PNG. Changing a control affects subsequent drawing, not every existing layer. Replace the source to begin another image; the new source clears the previous layer history. The editor does not save a project file containing these layers, and reloading the page does not provide a dependable way to recover unfinished work.

Why blur is inappropriate for some information

A blurred account number may retain its length, spacing or large character shapes. Pixel blocks can similarly preserve high-level structure, and other parts of a screenshot can disclose the same value in a header, status bar or notification. A visually pleasing effect is therefore a different decision from removing confidential content. For sensitive sharing, use an opaque covering over every occurrence, remove unnecessary surrounding material and inspect the saved file at full size. Do not rely on a thumbnail, an animation of the editor or a success notification alone. Consider whether the image needs to be shared at all when the remaining context is itself confidential.

Input and export boundaries

This workflow accepts nonempty PNG, JPEG and WebP raster inputs up to twenty MiB, no more than 8,192 pixels along either side and sixteen million pixels overall. Limits apply to the decoded image as well as the compressed file. Unsupported documents should be exported into an appropriate raster image before use, with the original retained separately. The output is PNG and includes the visible composited pixels, not the original file container or editor undo history. Canvas export is not a forensic certification that every identifying property, visual clue or external copy has disappeared. This tool does not certify compliance with a legal, medical or organizational redaction standard.

Check the saved copy, not just the preview

Open the downloaded PNG in a separate viewer. Inspect all corners, browser tabs, filenames, faces, reflections and small text surrounding the target region. Confirm that opaque regions completely cover the intended content and that annotations do not accidentally reveal it. If you change a layer or undo a step, download again and distinguish the new copy from an older result in your Downloads folder. Never attach the original source by mistake. A receiving application can generate thumbnails or backups, so your review should happen before upload. The editor cannot revoke copies already shared or remove the same information from another attachment.

Local processing and clipboard use

Image decoding, drawing and PNG creation take place in the browser without an image-redaction API. Pasting an image reads the clipboard content you supplied; it does not provide a secure clipboard or clear other clipboard history. The surrounding site can still load its normal assets, analytics and advertising under the privacy policy. Current image and layer state live in memory, while source files and downloaded PNGs remain under your filesystem controls. Closing or resetting the editor is not secure disk erasure. Use only a device, browser and storage location appropriate for the sensitivity of the material you are handling.

Troubleshooting and a stopping rule

If input decoding fails, the tool shows an error rather than leaving an earlier image available as a current export. Re-export the source as a supported raster format and retry it alone. If a rectangle appears in the wrong place, inspect the source at the current display size and draw again; undo the mistaken operation first. If drawing is difficult on a small screen, use a larger display before sharing confidential material. Stop when you cannot confidently inspect the entire saved result. Asking another authorized person to review a fictional rehearsal or the actual final copy can expose missed regions, but no second review replaces the need for an appropriate information-sharing decision.

Image Redactor - Cover and Annotate Raster Images