Compress Image to 20KB

How to compress an image to 20KB

1. Select your photo — JPG, PNG, WebP, HEIC and AVIF all work.
2. The target is already set to 20KB. Change it if you need a different ceiling.
3. Press Compress.
4. Check the result — it will be at or just below 20KB — and download.

When you need a 20KB image

20 KB is a genuinely tight budget, and it almost always comes from a form that refuses anything larger:

• Government and exam portals — application systems in India, Pakistan, Egypt and elsewhere routinely cap photo uploads at 20 KB, sometimes with a minimum of 10 KB as well.
• Signature fields — scanned signatures are usually limited to 10–20 KB and are the easiest case, since line art compresses extremely well.
• Forum avatars and small profile pictures displayed at 100 px.
• Email signatures, where every recipient downloads the image.

At this size a full-resolution photo is impossible, and that is fine: the target is nearly always displayed as a small thumbnail anyway.

How the 20KB compressor works

Hitting a byte target precisely is a search problem, not a formula. Here is what runs when you press the button:

1. Analyse. The image is decoded and measured — dimensions, format, whether it has transparency, and its true byte size.
2. Estimate. A first quality guess is derived from the ratio of 20KB to the original size. This is only a starting point, never the answer.
3. Binary search on quality. The image is re-encoded and measured, then the quality range is halved toward the target. Eight to twelve encodes are usually enough to land within a few percent.
4. Reduce dimensions, but only if needed. If even the lowest acceptable quality overshoots, the scale factor √(target / current) is applied with a small safety margin and the quality search restarts at the new size.
5. Refine upward. If the first success lands well under 20KB, the search tries a larger scale to spend the remaining budget on pixels rather than leaving it unused.

The result is the largest, sharpest image that still fits — not the first one that happens to be small enough. Landing at 20KB minus a hair is the goal; landing at a third of 20KB is a failure, even though it technically fits.

Getting the best quality at this size

Reaching 20 KB from a 5 MB phone photo means removing 99.6% of the data, so resolution reduction is unavoidable. To get the best result:

• Crop before you compress. A tight crop on a face wastes no bytes on background. This is by far the highest-leverage step at 20 KB.
• Expect roughly 400×500 pixels for a portrait. That is more than enough for a form thumbnail.
• Keep JPG as the output. WebP is smaller in theory, but many older government portals reject anything that is not JPEG.
• Avoid busy backgrounds. Noise is expensive; a plain wall behind the subject buys you noticeably more quality.

Will the quality drop?

Some quality is always lost when a large photo is squeezed into 20KB — the question is whether you will notice. The result panel shows an honest verdict:

• Excellent — indistinguishable from the original at normal size.
• Very Good — differences visible only when pixel-peeping.
• Good — fine for web and messaging use.
• Reduced — visible softening; acceptable for thumbnails and forms.
• Low — the target is aggressive for this image; consider raising it.

If you would rather keep every original pixel and accept whatever size results, tick Keep original dimensions in Advanced Settings — the tool will then solve with quality alone, and tell you if it cannot reach the target.

Supported formats

Input: JPG, PNG, WebP, GIF, BMP, HEIC/HEIF and AVIF. Output: JPG (default and smallest for photographs), WebP (smaller still, keeps transparency), or PNG (only sensible for flat graphics).

HEIC and AVIF decoders are downloaded on demand, so pages stay light for everyone who does not need them.