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Blur Image

Blur a whole image or a precise rectangular area locally, then download a full-resolution PNG.

Privacy: your files never leave your device. All processing happens locally in your browser.

How to use

  1. 1.Choose a JPG, PNG, or WebP image and confirm its displayed pixel dimensions.
  2. 2.Select the entire image or enter a rectangle, then set the blur radius.
  3. 3.Choose Blur image, inspect the preview and dimensions, and download the PNG.

About Blur Image

Blur Image is a focused browser tool for softening an entire picture or one rectangular portion of it. Upload a JPG, PNG, or WebP file, choose whether the effect should cover the full image or a rectangle, and adjust the blur radius from a light softening to a much stronger blur. Rectangle mode accepts X and Y coordinates plus width and height in original-image pixels, which makes the area repeatable and precise. The visible file dimensions help you choose sensible coordinates. If a rectangle extends beyond an edge, the tool safely clamps it to the available image area instead of expanding the output or failing unexpectedly.

The image stays on the device in the current browser tab. There is no upload step, remote processing queue, account storage, or server-side copy. Local processing is useful for ordinary photos, presentation assets, screenshots, draft graphics, and backgrounds that should not leave the computer merely to receive a visual effect. Supported inputs are JPEG, PNG, and WebP files up to 25 MB. A decoded-image safety budget also limits processing to 40 megapixels, because compressed file size alone does not reveal how much memory a browser needs for a canvas. Files outside those limits are rejected with a specific message before the blur is generated.

Preview quality and export quality have different jobs. The on-page canvas is reduced when necessary so a large photo remains practical to inspect in the browser. The downloadable PNG is not made from that reduced preview. Instead, the tool creates a separate offscreen canvas at the source image's natural pixel width and height, draws the original pixels there, and applies the selected blur at that full resolution. The result text reports those output dimensions before download. This separation prevents the common failure where a convenient 900-pixel preview silently becomes a low-resolution export. PNG is used for the output because canvas can produce it consistently without asking the server or installing a format-specific encoder.

Rectangle mode first paints the unmodified image, clips drawing to the clamped rectangle, and then paints a filtered version through that clip. Pixels outside the rectangle therefore remain as originally drawn. Blur kernels sample neighboring pixels, however, so colors and shapes close to the rectangle boundary can blend into the selected area. This is normal blur behavior and may be visible at a hard selection edge. Increase the rectangle size or radius when the transition needs more surrounding context, and inspect the downloaded file at full size rather than relying only on the smaller preview. For an evenly softened background, full-image mode is usually simpler.

Blur is not secure redaction. A blurred face, address, account number, license plate, document field, or private message may remain recognizable, recoverable, or inferable from context. Do not use this tool as proof that sensitive information has been permanently removed. For material that must be disclosed safely, remove or cover the source pixels with a suitable redaction workflow and verify the exported file, metadata, hidden layers, and surrounding context. This tool provides a visual blur effect for design and casual privacy needs; it does not certify anonymization, de-identification, or irreversible deletion.

A reliable workflow is to keep the original file, upload a working copy, choose the area and radius, generate the PNG, and open the download at 100 percent zoom. Check the selection boundary, output dimensions, and any text or faces that motivated the edit. If the area is wrong, update its pixel coordinates and generate again. Each new generation replaces the previous browser download object, while changing files or leaving the page releases temporary object URLs. The simple controls deliberately avoid automatic face detection, cloud analysis, or claims about what the image contains. You decide what to blur, and the browser performs only that requested pixel operation.

Methodology & sources

The browser validates a JPEG, PNG, or WebP file and enforces file-size and decoded-pixel budgets. A shared draw plan clamps the blur radius and rectangle in natural pixel coordinates, then derives a proportional preview plan. Rendering first draws the unchanged source and then clips a filtered full-image draw to the selected area. The preview uses scaled dimensions, while PNG export always uses a separate canvas at the source image's natural dimensions.

Frequently asked questions

Does the downloaded image keep its original dimensions?
Yes. The export is rendered on a separate natural-size canvas. The smaller on-page canvas is only a preview.
Is a blurred area permanently redacted?
No. Blur is a visual effect, not secure redaction, and sensitive details may remain recognizable or inferable. Use a verified redaction workflow when information must be irreversibly removed.
Are my images uploaded or stored?
No. Decoding, drawing, blurring, and PNG creation happen locally in your browser tab.

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