Blur an Image Area: what this tool does
Drag over a private detail or enter exact coordinates, then blur, pixelate or cover the selected area with a solid color. The source is decoded and processed in the current browser tab; CalculatorGeek does not receive the image bytes.
This page owns the blur image area online task. For the adjacent workflow, use Watermark Image, or return to the Image Tools Hub to choose another operation.
For the next related calculation, use the Photo Editor. Adjust brightness, contrast, saturation, hue, grayscale, sepia and softness, then choose the edited output format and quality.
How to use Blur an Image Area
- Choose a supported source image or enter the page-specific source content.
- Set the visible controls for this task.
- Inspect the processed preview, dimensions, format and measured byte size.
- Run the final action and download the result. Keep the original until you have checked the output.
To compare this result with another relevant method, open the Compress Image. Use this related conversion when its inputs match the next part of your problem.
Method and result meaning
The selected rectangle is mapped to source pixels. Blur redraws the clipped area with a filter, Pixelate downsamples and enlarges it without smoothing, and Solid redaction replaces it with the chosen color.
The result panel is the authoritative state for this session: it reports the rendered dimensions, encoded format and actual output bytes. The source file is never overwritten.
Which settings should you choose?
Choose settings from the destination requirement, not from a promise of universal quality.
- Use Blur for low-risk visual anonymization and Pixelate when a block treatment is easier to inspect.
- Use Solid redaction for text, account numbers or other details that must not remain visually recoverable.
- Drag the rectangle for speed, then verify or refine its exact pixel fields before downloading.
Worked example
For a 1200 x 800 image, X 420, Y 160, width 300 and height 260 limits the blur to that 300 x 260 rectangle. Increase the radius until details are no longer readable.
After completing this task, Crop Image handles the next distinct image operation without mixing its settings into this page.
Privacy, supported files and limitations
The tool does not detect faces or verify anonymization. Inspect the downloaded result at full size before sharing sensitive material.
Processing is local to the browser. Each input is limited to 25 MB and 80 megapixels, each output to 64 megapixels, and batch-capable tools accept up to 20 files. Animated inputs use the decoded still frame.
Inputs, outputs and result meaning
The selected rectangle is mapped to source pixels. Blur redraws the clipped area with a filter, Pixelate downsamples and enlarges it without smoothing, and Solid redaction replaces it with the chosen color.
Inputs
- Source width
- Decoded source width in pixels. Supported units are px.
- Source height
- Decoded source height in pixels. Supported units are px.
Outputs
- Decoded source pixels
- This is the primary result. It is displayed in px. The display rule uses up to 0 decimal places.
The documented method is applied after the inputs are validated and normalized. Keep the result label, unit, selected mode, and stated limitations together when sharing the answer.
Frequently asked questions
Does the tool find faces automatically?
No. You drag or enter the rectangle. The page does not claim automatic face detection.
Is blur always enough for sensitive information?
Not necessarily. Confirm the exported pixels at full resolution; for high-risk material, solid redaction is the stronger visible choice.
Sources and method transparency
The implementation and its stated limits were reviewed on October 14, 2026 against the following browser-platform documentation.
- MDN - CanvasRenderingContext2D.drawImage() - Documents the browser drawing, scaling and source-rectangle operation used by the image pipeline.
- MDN - HTMLCanvasElement.toBlob() - Documents browser canvas encoding and format fallback behavior.
- MDN - CanvasRenderingContext2D.filter - Documents the filters applied during image drawing.