To compress image to 20KB, do two things in order: crop the photo down to roughly ID-photo dimensions first, since this tool does not resize yet, then drop it in the box above as JPEG and lower the quality slider a step at a time, checking the file size after each pass until it reads 20 KB or under.
That order is the whole trick, and most guides skip the first half. A 20 KB ceiling is not a quality problem, it is a dimensions problem wearing a quality costume. Get the pixel count down and the quality slider barely has to work; skip the crop and no slider setting will save you. The tool re-encodes and strips EXIF by default, so the only manual step left is the crop your phone already does.
Why 20 KB is the strictest upload cap you will hit
20 KB is the smallest limit any normal upload form imposes, and it is almost always a government one. Passport and visa applications, public-service exam portals, university admission forms, licensing boards, and a fair number of avatar fields all cap a photo at exactly 20 KB. These forms were built around a small, low-resolution ID headshot, not the four-to-six-megabyte original a phone camera hands you. Arrive with that original and the upload bounces before anyone looks at it, because the number the form checks has nothing to do with how the photo looks.
The math is the reason. A standard passport or ID photo is 2 inches by 2 inches, which at a typical 300 DPI print resolution is 600 by 600 pixels, a little over a third of a megapixel. A 12 megapixel phone photo cropped to that square is carrying roughly 3 percent of its original pixel count. That is why the crop matters more than any quality setting: after it, there is far less data left to encode, and 20 KB stops being a fight. For the wider set of portal and form rules, the guide to compressing images for uploads walks through the caps site by site.
How to compress image to 20KB for a form
Here is the sequence that actually clears the cap, in the order that matters.
- Crop first, in your phone or OS photo editor. Cut the frame down to the square or portrait the form specifies (most ID specs want a head-and-shoulders crop, not the whole scene). This tool does not resize or crop yet, so this one step happens outside it.
- Upload the cropped photo to the box above and set the output to JPEG. JPEG encodes photographic detail smaller than PNG at the same visual quality, and it is the format nearly every government portal expects.
- Lower the quality slider below the default 80 in steps, checking the file size the tool shows after each pass. There is no automatic hit-exactly-20-KB mode, so this is two or three tries, not one click.
- Judge the result before you submit. If the quality it takes to clear 20 KB leaves a face or signature hard to read, crop tighter instead of pushing the slider lower, because dimensions buy you file size far more cheaply than quality does.
That is the entire method. The crop does most of the work, the quality slider does the finish, and the file size counter tells you the moment you have cleared the wall.
Why the quality slider alone will not get you to 20 KB
Quality trims file size by re-encoding detail a screen would not miss, but the pixel dimensions set a hard floor under how far that can go. A full-size phone photo has millions of pixels to encode no matter how low the quality number drops, so forcing one down to 20 KB without cropping means visible blockiness long before you reach the number. On a 600 by 600 crop the same slider has a third of a megapixel to describe instead of twelve million, so a mild quality drop clears 20 KB with the face still legible.
This is also why 20 KB behaves so differently from a looser cap. If a form let you send 50 KB you could often skip the crop, which is exactly the case the 50 KB page covers. At 20 KB the crop is not optional, it is the step that makes the compression possible at all.
A whole batch of ID photos in one pass
Schools photographing an incoming class and HR teams onboarding a group hit the same 20 KB rule dozens of times, not once. Crop every photo to the same dimensions first, then upload up to 30 of them here as a single batch instead of repeating the crop-then-compress cycle by hand. Every image in the batch takes the same quality setting unless you change it, so a full cohort comes out consistent, all clearing the same limit together rather than some slipping through at a slightly different setting. The batch cap is 30 images at a time with no signup, far more headroom than a single ID photo needs.
What the tool does to your file
Every file gets its EXIF data stripped automatically, the hidden metadata a camera writes in including GPS coordinates, camera model, and timestamp, on top of whatever quality you pick. You do not have to hunt for the option; it is off the moment the smaller file comes back. Files dropped into the browser tool are deleted within an hour by a sweep that runs every 15 minutes, and the only way to reach one before that is a signed link that expires in 15 minutes. Nothing sits in a public bucket and nothing you upload is used to train a model or looked at by a person.
The tool itself is free with no signup, up to 25 MB per image and 30 images a batch, repeatable as often as you want. A free account adds a running total of 100 images a month and a usage dashboard. Doing this at volume, or from your own code, is where Pro at 12 dollars a month flat comes in, with files up to 50 MB and batches of 100. Full tiers are on the pricing page. None of that changes the method: crop first, compress second.