Mark an image or soften an area, then inspect the exported pixels
Watermark mode adds text to draft artwork, sample photographs or review screenshots. Blur and pixelation change a rectangle chosen with percentage coordinates. Edits are encoded into a new image, not stored as removable overlay controls.
Blur and pixelation can leave recognizable outlines, character lengths or other clues. A stronger setting does not prove that identifying information is safe to publish. Crop sensitive content completely out where possible; otherwise use a suitable redaction method and verify its output.
Choose the edit and output format
| Your situation | Recommended approach |
|---|---|
| Mark a review image as SAMPLE | Choose Watermark and use short text. A single mark sits diagonally across the centre; Repeat across image distributes marks over the picture. |
| Reduce a distracting area without deleting it | Choose Blur area and inspect the entire region after export. This is a visual effect, not a confidentiality guarantee. |
| Create a deliberate block-pixel effect | Choose Pixelate area. Increase Strength to enlarge the block effect, while checking that the chosen rectangle covers the intended area. |
| Keep sharp screenshot text or transparency | Start with PNG. JPG uses lossy encoding and fills transparent areas with white; WebP can be useful when your recipient supports it. |
Compare a watermark with a separate, measurable blur
The 1200 × 800 document-photo.png sample relates percentage settings to a measurable area without using private information.
- Choose document-photo.png, select Watermark, enter SAMPLE, set Opacity to 35% and leave Repeat across image unchecked. Choose PNG, apply watermark and download the result.
- Reset the result and select Blur area. Set X to 25, Y to 25, width to 50, height to 50 and Strength to 14. Keep PNG output.
- Apply blur and download this separate result. The selected region starts 300 pixels from the left and 200 pixels from the top, spanning 600 × 400 pixels.
- Compare both exports with the source at full resolution. Inspect the watermark, blurred rectangle and untouched border separately.
Expected result. Both outputs retain 1200 × 800 dimensions. One has a diagonal SAMPLE label; the other blurs the centre. Changing modes processes the selected source again and does not combine edits. This example verifies a visible effect, not secure removal of information.
Check the downloaded result
- Open the downloaded file at full resolution. A small preview can hide surviving letters and edge details.
- Check all four rectangle edges. X and Y start from the left and top; width and height are percentages of the whole image.
- Inspect the remaining image for names, reflections, badges and other identifying details outside your rectangle.
- Confirm dimensions, file type and transparency. Attach the reviewed export rather than the similarly named original.
Troubleshooting
- The selected image area is invalid
The rectangle extends beyond an image boundary or contains an empty dimension. Each individual value being below 100 is not enough.
Try this: Ensure X + width is at most 100 and Y + height is at most 100. Use positive width and height; for the whole image, enter 0, 0, 100, 100.
- The effect misses the intended detail
Coordinates refer to the entire decoded image, not the visible size of its preview. A percentage covers more pixels on a larger image.
Try this: Adjust the rectangle using the full image dimensions, regenerate and inspect the exported edges. Do not use a partial blur as evidence that sensitive information has been removed.
- A watermark is cut off or dominates the picture
The mark uses a fixed diagonal orientation and a font size derived from image dimensions; there is no separate font-size or placement control.
Try this: Shorten the text and lower opacity where needed. Compare a single mark with Repeat across image and choose the version that leaves necessary content readable.
- The image cannot be opened or processed
Decoding support varies by image format and browser, and large decoded images need much more memory than their compressed file size suggests.
Try this: Try a JPG or PNG copy, check the limit displayed by the picker, and reduce source dimensions if the memory error persists. HEIC/HEIF selection does not guarantee the current browser can decode it.
- Blur reports an unsupported browser and produces no result
Blur requires a native canvas filter that some WebKit or Safari browser environments do not provide. The tool stops rather than offering an unchanged image as a blurred result.
Try this: Try the visual blur in a supported Chrome or Firefox browser. Pixelation is another visual effect you can consider, but neither effect guarantees secure redaction of sensitive information.
Limits and compatibility
- Local processing
- The browser processes your image without overwriting the original. Keep that source if you need to change the edit later.
- Scope of the controls
- There is one rectangular area per run, no automatic face or text detection, and no promise that watermarking prevents copying. To combine edits, download and select the reviewed result for the next operation.
Your files and form values are processed on this device. Downloaded copies remain wherever you save them. See how to check local processing and our privacy policy for site data and optional services.
Common questions
- Is pixelation a secure way to hide a document number?
- Do not rely on it for that purpose. The visual effect can retain information and the tool does not measure resistance to reconstruction or inference. Remove the sensitive pixels using an appropriate workflow before publishing.
- Why is my PNG larger than the original JPG?
- PNG preserves pixels without JPG's lossy compression. File size can increase even when the edited image looks simpler. Choose a format based on required detail and transparency, then inspect any lossy export.
Continue your document workflow
Maintained by Shakti Prasad Ram. Found a mismatch? Report the tool, browser and steps without sending a sensitive document. Back to the tool