"Photo size should be between 20 KB to 50 KB" — what it means and how to fix it
This message means your photo is outside a range, not simply too big. It is failing the 20 KB floor about as often as the 50 KB ceiling. Here is how to tell which, and fix it.
The word doing the work in that message is between. It is a range with two ends, and almost everyone reads only the upper one. They compress the photo harder, it gets smaller, and the same message comes back — because the file has now fallen under the 20 KB floor instead.
Which end are you failing?
Look at the file on your own device before touching it. On a phone, open it in the gallery and check details or info; on a computer, right-click and choose Properties or Get Info. If it reads under 20 KB you are failing the minimum. If it reads over 50 KB you are failing the maximum. If it sits between the two and the portal still refuses it, the size is not your problem at all and you should stop compressing — see the last section.
If the file is too large
Do not simply compress. Set the pixel dimensions first, because a photo that is 3000 pixels wide will never sit comfortably at 50 KB and anything that forces it there will look destroyed. Set the width and height the notification asks for, then let the quality be chosen to fit the range. The exam photo resizer does both in one step: give it the pixel size and the two KB figures and it finds the best quality that lands inside them.
If the file is too small
This is the case nobody expects, and it is common. A photograph taken against a plain white wall compresses extremely well, because a flat background costs a JPEG almost nothing to store. A perfectly good photo can land at 12 KB and be rejected for it.
The fix is not to make the picture worse. A JPEG can carry comment segments that every decoder skips, so the file can be padded up to the floor while the picture stays exactly as it is. Set the minimum in the tool and it does this automatically, and the result is still a valid JPEG that any portal will open.
If the file is already inside the range
Then the message is lying to you slightly — portals often show one generic size message for several different failures. The usual real cause is the pixel dimensions, which the portal checks separately and rarely mentions. The second is the format: a file renamed from .png to .jpg is still a PNG inside, and the portal reads the bytes.
Rather than guessing, put the numbers from your notification into the rejection checker and drop the file in. It tests every rule separately and names the ones that fail, so you fix the right thing once instead of the wrong thing four times.
Questions
What KB should I aim for between 20 and 50?
Around 35 KB. It leaves room at both ends, so a portal that rounds differently or re-encodes on upload still lands inside the range.
Why is my photo under 20 KB when I did not compress it?
A plain background compresses very efficiently. Flat areas cost a JPEG almost nothing, so a clean passport photo routinely comes out in the low teens.
Is padding a file to reach the minimum safe?
Yes. The padding goes into JPEG comment segments, which every decoder is required to skip. The image data is untouched and the file opens normally everywhere.
Can I just take a screenshot to change the size?
No. A screenshot changes the pixel dimensions to whatever your screen is, which usually breaks the dimension rule while fixing nothing.