A worked example
On a detailed 4032 × 3024 test photograph set to 200 × 230 pixels with a 20–50 KB range, the search settled at quality 94 and 23,064 bytes. The same photograph with only a 50 KB limit and its pixels kept could not get there — the smallest JPG at full size was 555 KB — so the page said so and offered Allow fewer pixels, which stepped the size down to 1025 × 769 and landed at 49,425 bytes. Each attempt is a real encode in a worker thread, and the number beside Save is the length of the file it will hand you.
| You type | The page aims for | Why |
|---|---|---|
| Max 50 KB | at most 50 000 bytes | Under both 50 × 1000 and 50 × 1024 |
| Min 20 KB | at least 20 480 bytes | Over both 20 × 1000 and 20 × 1024 |
| Max 1 MB | at most 1 000 000 bytes | The stricter of the two readings |
When another page here fits better
If the form also gives a pixel size for a photo or a signature, start from the exam-form page or the signature page: their presets set the pixels and the KB range together. If you only want a smaller file and no particular number, reduce image size shows the before and after bytes instead.
What stays on your device
Every encode in the search happens in a worker inside this tab. No attempt, no file name and no byte count is sent anywhere; the search runs the same with the network switched off once the page has loaded.
A kilobyte limit is met by discarding detail. Below quality 50 the page says the compression is heavy, because faces and text start to look blocky; if that matters, allow fewer pixels instead, which usually looks better at the same size.
Questions people ask here
Why is my 50 KB file 48.7 KB and not exactly 50?
Because a JPG's size moves in steps as the quality moves, and the search keeps the best quality that lands at or under the limit. The page aims at 50 000 bytes rather than 51 200, so the file passes whichever way the form counts a kilobyte.
Will the pixel size change?
Not unless you let it. By default only the encoder's quality moves. If the lowest quality this page uses is still over the limit, it says so and offers Allow fewer pixels, which steps the size down by 10% at a time and prints the new size in the receipt.
Can a PNG be made 20 KB?
Usually not at a photographic size. PNG has no quality dial, so the page writes it once and tells you where it landed. Switching to JPG is one tap, and JPG is what most upload forms ask for anyway.
The form says at least 20 KB. Can it make a small file bigger?
It raises the quality, up to the encoder's maximum. If even that is under the minimum, it tells you, and a larger pixel size is the honest way to add bytes. It does not pad the file with filler.