Application systems for exams, banking, universities and government services frequently ask for a signature image between 10 and 20 KB. A phone photo or flatbed scan of your signature comes out at hundreds of KB or several MB, so heavy compression is unavoidable. The good news: signatures are exactly the kind of image that survives aggressive compression well — high contrast, few colors, no gradients.
Compress your signature now: set the target to 20 KB (or 10 KB), pick JPG, and download a form-ready file in seconds.
Compress my signatureWhy signatures compress so well
A signature is dark ink on light paper. Almost every pixel is near-white or near-black, which means the image carries very little information per pixel. Lossy JPG compression preserves this kind of content cleanly even at low quality — there are no skin tones or gradients to degrade. A 600×200 pixel signature at 20 KB usually looks indistinguishable from the original at normal viewing size.
Capture tips before you compress
- Use plenty of light and keep the camera parallel to the paper, so the background is evenly white and the strokes are sharp.
- Sign on plain white paper with a dark pen — blue or black ink both work.
- Crop tightly around the signature before compressing. Extra desk, shadows and margins waste your byte budget on pixels nobody needs.
- Clean the background if you can — most phone photo apps have a document/scan mode that whitens the paper.
Compressing to 20KB step by step
- Open the JpegDiet compressor on this site.
- Upload your cropped signature image.
- Set target size to 20 KB (use the Custom option for 10 KB limits).
- Output format: JPG — most form systems expect .jpg/.jpeg for signatures.
- If the form also specifies dimensions (commonly 140×60 or 250×100 pixels), set "Max dimensions" accordingly.
- Download and verify the file size before uploading.
What if my form requires PNG for the signature?
Some systems ask for PNG with a transparent background. Since PNG is lossless, a 20 KB PNG only works at very small dimensions or with heavy color reduction. Practical approach: resize the image to the exact pixel dimensions the form specifies (that alone often brings a scanned signature under 20 KB as PNG), and if it is still over, reduce colors to black-and-white or a small palette in an image editor first.
Typical signature requirements
| Context | Common requirement |
|---|---|
| Government exam applications | JPG, 10–20 KB, fixed pixel size |
| Bank account opening forms | JPG/PNG, 10–50 KB |
| University admissions | JPG, 20–100 KB |
Requirements vary — always follow the exact limits shown on your specific form, and remember that a tool with a guaranteed maximum size removes the guesswork from hitting them.