How to blur or redact sensitive information in a screenshot

Reduce exposure before editing

Capture the smallest useful region and close private notifications. Cropping a password manager, email sidebar, or account menu completely out of the image is safer than covering it later. Keep an untouched original in a protected location when the screenshot is evidence.

Distinguish blur from redaction

Blur and pixelation preserve a transformed version of the underlying visual structure, which is useful for presentation but can be a poor confidentiality boundary. Permanent black redaction replaces the selected pixels with a solid value in the exported bitmap. An annotation rectangle that can be moved later is not the same as a flattened redaction.

Use automatic detection as a review aid

The frozen build can locate sensitive email regions locally, but the published fixture deliberately demonstrates the limit: the email is covered while a phone number remains visible for manual review. Automatic detection must never be described as complete privacy verification.

1. Crop unrelated content
2. Run local sensitive-region detection if useful
3. Review every suggested region
4. Add manual redactions
5. Flatten to a separate output
6. Reopen and inspect every private value

Verify the final pixels

Do not rely on the editor canvas alone. Open the exported image in another viewer, zoom in, inspect the edges of every box, and confirm that copyable text, metadata, filenames, and nearby context do not reveal the value indirectly.

Failure modes and limits

Automatic detection can miss phone numbers, names, IDs, addresses, faces, or unusual text. Blur and pixelation may not meet a policy that requires irreversible removal.

Stop when the capture omits required context, a scroll seam repeats or skips content, a recording stream cannot be decoded, OCR changes a critical value, or a redaction leaves private information visible.

Recovery and verification

Return to the untouched original or .uvcap project, add or resize redactions, export a new file, and repeat independent visual inspection.

Record the application version, capture target, pointer and delay settings, scroll axis or audio choice, output format, and final artifact hash when the result must be reproducible.