How can I verify the image isn't uploaded?

Open your browser's DevTools (F12) and go to the Network tab. Compress an image while watching for requests. No outbound connections appear because all processing happens locally in your browser tab using the Canvas API.

Why compress images without uploading?

Some files are not appropriate to send to a third-party service, and some networks block uploads altogether. Processing locally avoids both problems.

Which image formats are supported?

JPEG, PNG, and WebP are supported as inputs. The output is a compressed JPEG.

How much can I reduce an image's file size?

File size reduction depends on the original image and the quality setting you choose. A typical photograph can be reduced by 40–80% while remaining clearly legible.

Compress Image Without Uploading

Reduce your image file size entirely in your browser. All processing runs in your browser, with nothing visible to a third party. Drag and drop your image, adjust the quality slider, and download the compressed result.

Drop an image or click to choose

JPG, PNG, or WebP, up to 50 MB. Stays in your browser.

FORMAT

QUALITY 80%

Runs entirely in your browser

How it works

Dropping an image triggers the Canvas API to decode the pixels in-memory, with no upload step. Moving the quality slider re-runs ctx.canvas.toBlob('image/jpeg', quality) so you can preview the size and visual result before downloading. Everything from decoding to encoding to the final download happens inside this browser tab.

Processing runs in your browser

Open DevTools to the Network tab while you drop an image and adjust the quality slider, and you will see zero outbound requests. The Canvas API encodes locally; no upload step occurs. You can confirm this yourselfin your browser's DevTools Network tab.

Related operations

If you need a different file format after compressing, try the image converter. To trim images to a specific aspect ratio first, use image crop. For multi-image PDFs from compressed photos, see image to PDF.

Frequently asked questions

How can I verify the image isn't uploaded?: Open your browser's DevTools (F12) and go to the Network tab. Compress an image while watching for requests. No outbound connections appear because all processing happens locally in your browser tab using the Canvas API.
Why compress images without uploading?: Some files are not appropriate to send to a third-party service, and some networks block uploads altogether. Processing locally avoids both problems.
Which image formats are supported?: JPEG, PNG, and WebP are supported as inputs. The output is a compressed JPEG.
How much can I reduce an image's file size?: File size reduction depends on the original image and the quality setting you choose. A typical photograph can be reduced by 40–80% while remaining clearly legible.

Compress Image Without Uploading

How it works

Processing runs in your browser

Related operations

Frequently asked questions

Related tools