Compress Image to KB: Reduce Photo Size to Any KB Online

How to use the Compress Image to KB

1Pick the maximum size the form allows, such as 50 KB, or choose Custom.

2If the form also gives pixel limits, enter them as max width and height.

3Choose or drop your photo, signature or scan. Batches work too.

4The tool finds the best quality that fits and shows the final size.

5Download the JPG and upload it to the form.

Why forms ask for an exact size

Online application portals for exams, jobs, scholarships, passports and bank accounts limit the size of every upload. A phone photo is usually 2–5 MB, but the form may demand “photo between 20 KB and 50 KB” and “signature under 20 KB”. Upload anything bigger and the portal rejects it, often with no clear reason.

This tool takes any photo, scan or signature and produces a JPG that is at or under the size you choose, at the highest quality that fits. It works in your browser, so ID documents and signatures never leave your device. If your form names one of the usual limits, the preset pages go straight to it: compress image to 20KB, 50KB, 100KB or 200KB.

How the tool hits the target

The file size of a JPG depends on two things: the quality setting and the number of pixels. The tool searches for the best combination:

It measures the file at a low quality (45) and a high one (92). If quality 92 already fits, you get that.
Otherwise it searches the quality scale, measuring the real file each time, until it finds the highest quality at or under your limit. It stops when the file is within about 3% of the limit.
If even quality 45 is too big, there are simply too many pixels for the limit. The tool scales the image down just enough (keeping its shape) and searches again.

New size ≈ old size × √(target bytes ÷ current bytes)

Because file size grows roughly with the number of pixels, shrinking both sides by the square root of the ratio lands close to the target in one step. Every result is checked after it is made, so it is never over the limit. Untick Allow smaller dimensions if the image must keep its pixel size; the tool will then lower the quality further instead, or tell you the target cannot be reached.

Worked examples with real numbers

We ran a 1920 × 1200 landscape photo (420 KB) and a 3840 × 1200 panorama (1.25 MB) through the tool:

Photo	Target	Result	Quality	Size in pixels
1920 × 1200, 420 KB	100 KB	97.2 KB	76	1920 × 1200 (unchanged)
1920 × 1200, 420 KB	50 KB	49.1 KB	45	1920 × 1200 (unchanged)
1920 × 1200, 420 KB	20 KB	19.4 KB	48	1048 × 655
3840 × 1200, 1.25 MB	50 KB	49.6 KB	58	2566 × 802
3840 × 1200, 1.25 MB	20 KB	19.5 KB	66	1623 × 507

Notice that for the tightest targets the tool kept a decent quality (48–66) and reduced the pixel count instead. That looks far better than squeezing a large photo down to quality 10.

Common size rules on application forms

These are the limits many portals have used. Rules change between notices, so always check the current advertisement before you upload.

Portal (examples)	Photo	Signature
IBPS bank exams (India)	20–50 KB, 200 × 230 px	10–20 KB, 140 × 60 px
SSC exams (India)	20–50 KB	10–20 KB
Bangladesh government jobs (Teletalk)	up to 100 KB, 300 × 300 px	up to 60 KB, 300 × 80 px
Many university and job portals	50–200 KB	20–50 KB

For the pixel sizes, enter them as Max width and Max height. If the form wants an exact size such as 200 × 230 with no other shape allowed, first make the shape right with Crop Image (use a custom ratio) or Resize Image, then compress here.

KB, KiB and why we aim a little lower

Some websites count 1 KB as 1,000 bytes; Windows and many portals count 1,024 bytes. A file of 50,500 bytes is “49.3 KB” in one system and “50.5 KB” in the other, so it could be rejected by a 50 KB limit. This tool treats 1 KB as 1,000 bytes, so a “50 KB” result is at most 50,000 bytes and passes under both rules.

Tips for photos and signatures

Crop first. Cut the photo to your head and shoulders before compressing. Fewer pixels of background means more quality for your face.
Signatures: sign in black or dark blue ink on plain white paper and photograph it in daylight. A clean, high-contrast scan compresses to 10–20 KB without losing sharpness.
Scanned certificates: if a form wants a document as a PDF under a limit, convert with JPG to PDF, and use Compress PDF if it is still too large.
No exact limit? If you just want smaller files, Compress Image gives you a quality slider and a before/after view instead.

Frequently asked questions

Will the file really be under the limit?

Yes. Every result is measured after it is created and is never larger than the size you chose. We count 1 KB as 1,000 bytes, which is slightly stricter than 1,024, so the file passes either way.

How do I compress a photo to 20 KB without it looking blurry?

Small limits need small images. Most forms with a 20–50 KB limit only need about 200 × 230 pixels for a photo or 140 × 60 for a signature; at that size 20 KB gives a sharp result. Enter the pixel size if the form states one.

Why is the result saved as JPG?

Almost every exam, job and government portal accepts JPG, and JPG gives the best quality at a fixed size for photos and scans. PNG files with transparency get a white background.

My image is already smaller than the limit. What happens?

If your JPG is already under the limit, you get the original back with hidden metadata removed. Other formats are converted to JPG at the highest quality that fits.

Can it make a file bigger, for a minimum size like "between 20 KB and 50 KB"?

The tool aims as close to the maximum as it can, usually within 3%, so a 50 KB target normally lands between 48 and 50 KB. It does not add padding to small images.

Are my documents uploaded?

No. Photos, ID scans and signatures are processed in your browser and never leave your device.