To compress an image to 20 KB, select Choose images, check that Target size reads 20 KB, and select Compress. The tool lowers the JPG quality step by step and, if that isn't enough, shrinks the dimensions until the file is under 20 KB. Each result shows its final size and the quality used, with its own Download button.
How to compress an image to 20KB
- Choose your images. Select Choose images and pick a JPG, PNG or WebP file, or up to 50 at once. Nothing is uploaded.
- Check the target. Target size is already set to 20 KB. If a form says "maximum 20 KB", type 19 to leave a small safety margin.
- Set a max width. Keep the output on JPG, which nearly every form accepts. For a signature, a Max width of 400-600 pixels works well; for a small photo, try 300.
- Compress and download. Select Compress. Each image shows its original size, final size, dimensions and quality. Select Download, or Download all (ZIP) for a batch.
Where the 20 KB limit comes from
A 20 KB cap shows up most often on Indian recruitment and exam forms, usually for the signature. Here are examples from recent official notices:
| Upload | File size | Preferred pixels | Example |
|---|---|---|---|
| Signature | 10-20 KB | 140 x 60 | Punjab & Sind Bank and CSIR-NGRI recruitment |
| Photograph | 20-50 KB | 200 x 230 | The same notices |
| Signature | 10-20 KB, JPEG | About 4 x 2 cm | SSC exams, where the photo is captured live instead |
Two details catch people out. First, many forms set a minimum as well as a maximum, so a 6 KB signature can be rejected just like a 40 KB one. Second, the numbers change between notices. Check the advertisement you're applying to before you upload, and match its pixel size as well as its file size.
Signature 20 KB upload: how to keep it readable
- Sign clearly. Use black or dark blue ink on plain white paper, which is what the notices ask for. Thin, faint pen strokes blur when the file is compressed.
- Scan or photograph it flat. Daylight and no shadows give a clean white background, and clean backgrounds compress well.
- Crop tight. Remove the empty paper around the signature with Crop Image. Every blank pixel costs bytes.
- Keep enough pixels. In our tests, a 600 x 250 signature landed under 20 KB at good quality, while a 140 x 60 one was only 2-5 KB even at maximum quality. That's below the common 10 KB minimum, so don't shrink a signature further than the form asks.
If your signature is a PNG with a transparent background, the transparent areas turn white when it's saved as JPG, which is what forms expect.
What fits in 20 KB: pixel sizes that work
File size depends mostly on how many pixels an image has, and then on how much detail is in it. These figures come from test images saved as JPG. Busy backgrounds, noise and fine patterns need more bytes.
| Image | Pixel size | Result at 20 KB |
|---|---|---|
| Signature | 140 x 60 | Well under, about 2-5 KB at any quality |
| Signature | 600 x 250 | Fits at roughly 75-80% quality |
| Head-and-shoulders photo | 200 x 230 | Fits at high quality |
| Head-and-shoulders photo | 300 x 400 | Fits at around 65-70% quality |
| Phone photo | 4000 x 3000 | Only after heavy shrinking, at low quality |
If a form allows 50 KB for the photo, use the 50 KB compressor instead. The extra room keeps a face much clearer.
Why resizing first helps when you compress an image to 20KB
The compressor tries quality first. It searches between about 95% and 30% JPG quality for the highest setting that fits. Only if the image is still too big at the lowest quality does it scale the dimensions down, 10% at a time, until the file fits.
For a full-size phone photo, that means it hits the 30% floor and then shrinks repeatedly. The result fits, but at the lowest quality, so you see blocky skin and smeared edges. Set Max width first, around 300 pixels for a photo, and the image starts small enough that the search can stop at 70% or higher. If the form asks for an exact size like 200 x 230, make it with the image resizer before compressing, since Max width only limits the width.
Frequently asked questions
How do I reduce photo size to 20 KB?
Choose the photo, leave Target size at 20 KB, set Max width to about 300 pixels and select Compress. The result shows its final size so you can confirm it's under the limit.
Can I resize an image to 20 KB without losing quality?
Some loss is unavoidable at 20 KB, but you can keep it small by reducing the pixel size first. A 300 x 400 photo at 70% quality looks far better than a large photo squeezed down at 30%.
What size should a signature be for a 20 KB limit?
Many bank recruitment notices ask for 10-20 KB at a preferred 140 x 60 pixels. A tightly cropped signature 400-600 pixels wide usually lands inside that file size range.
My form needs between 10 KB and 20 KB. How do I hit that range?
Set the target to 19 KB. If the result comes out under 10 KB, the image has too few pixels, so clear Max width or start from a larger scan.
Can I compress a PNG to 20 KB?
Yes. The PNG is saved as a JPG or WebP, because PNG can't reach small sizes for photos. Any transparent background becomes white in a JPG.
Why does the form still say my file is too big?
Some sites count a kilobyte as 1,000 bytes and others as 1,024. Aim one or two KB under the limit, for example 19 KB for a 20 KB maximum.
Is this image compressor to 20 KB safe for ID documents?
Yes. Compression runs in your browser, so your photo and signature never leave your device or reach a server.