The quick way
- Open the page for your limit: 20 KB, 50 KB, 100 KB, or Compress Image and type any size in Target size (KB).
- Drop in your photo. It is saved as a JPG at the highest quality that fits under the limit.
- Download it. The new size is shown next to the file.
The photo is processed on your own device, which matters for passport photos and signatures.
Why a small limit needs a smaller picture
A phone photo is often 3 to 5 MB: 4000 pixels wide or more. Lowering the JPG quality alone cannot bring that down to 20 KB without turning it into blocks, so the width and height have to come down too. A passport-style photo of about 300 × 400 pixels fits comfortably in 20 to 50 KB and still looks sharp on screen.
If the form also asks for exact dimensions, set those first with Resize Image, then compress.
Signatures
Sign on plain white paper with a dark pen, photograph it in good light, and crop it close to the signature. A tightly cropped signature of 300 × 100 pixels is usually well under 10 KB.
What "KB" means on a form
Some sites count 1 KB as 1,000 bytes and others as 1,024. The compressor keeps the file under the lower number, so it passes either way. If a form still rejects it, check the file type: many forms accept only JPG, not PNG or HEIC.
A phone photo brought down to 20 KB
- Start: a 4032 × 3024 photo of about 3 MB.
- Crop to the face and shoulders in the shape the form asks for, often 3:4 or square.
- Resize to the required size, for example 300 × 400 pixels. The file is now far smaller before any quality change.
- Compress to the target. A plain light background compresses better than a busy room behind you.
Common problems
- The form says the file is too small. Some forms have a minimum, for example 10 KB. Use a larger size or a higher target, rather than the smallest file possible.
- The form asks for a DPI value. DPI is only a label stored in the file. It does not change the pixels or the file size. Set the pixel size the form asks for.
- The photo looks blurry or blocky. The picture is too large for the limit. Crop tighter or reduce the pixel size, rather than lowering quality further.
- The background color is wrong. Many forms require a white or light background. Fix that in the original photo, since compression will not.