UnderKb

Free image compressor

Compress an image to KB

Set a kilobyte budget. We drop quality first, then scale pixels if needed. No account. Convert, resize, and the other jobs live on their own pages — same dropzone idea.

How it works

  1. Drop the image

    JPG, PNG, WebP, or GIF (first frame). Free 20 MB, one file. A Pro key on /pricing allows 50 MB or a ZIP of 20. On a phone you can pick from the camera roll and Share the result.

  2. Set the budget

    200 KB is the default — forms, email, and LMS caps. 50 KB for thumbnails. 500 KB for a lecture slide.

  3. Download

    The file stays available for about 30 minutes. We do not keep a gallery of your pictures.

Other jobs

Convert to WebP, resize or stretch, cut a flat background, or copy a HEX palette. The compressor on this page is the default.

Compress to KB

Hit 50, 200, or 500 KB. Quality first, then scale.

Open tool

JPG to WebP

Turn JPG or PNG into WebP (or back). You set the quality.

Open tool

Resize

Change width and height. Fit, crop, or stretch.

Open tool

Remove background

White or flat backdrop → transparent PNG. Not a portrait cutout.

Open tool

Extract colors

HEX palette with an approximate share. Copy the codes.

Open tool

Guides

The same jobs, written out: 200 KB, WebP, resize, and a white background.

FAQ

Can I compress a JPG to 200 KB?

Yes. 200 KB is the default target. You can set 50, 100, 500, or 1024 KB.

Does UnderKb store my images?

The compressed file is kept in memory for about 30 minutes so you can download it, then it expires.

Do I need an account?

No. Drop a file, download. Ads may appear around the tool.

Does remove background work on portraits?

Only flat backdrops (studio, white). It is not an AI people matte. Open Remove background for that job.

Is there a KB extension?

Yes. The Chrome extension opens compress, WebP, resize, a flat-background cut, and the palette. The file is still processed on this site.

Can I stretch an image?

Open Resize and choose Stretch. Fit keeps the aspect ratio. Fill crops to the box.

Can I compress to 2 KB?

The smallest target is 8 KB. A photo that small is scaled down hard. 200 KB is the default for forms and email.