Five photos of a handwritten form
Add all five JPG files, order them, and keep 500 KB selected. Handwriting needs more pixels than printed type. If the readable copy is under 500 KB, download it. If a page looks faint, do not shrink further.
Compress PDF to 500 KB
A PDF that already fits is returned as-is. A bigger PDF is rebuilt as images, so you cannot select the text afterwards.
Page order
About this size
500 KB is the roomier cap. Three to five photos of a form, or a longer scan, often land under 500 KB without looking soft. Use it when the form says 500 KB. Do not pick 500 KB if the form says 100 KB. The portal will still reject the file.
How to use it
- Set the size written on your form. Use Custom if the number is not on a chip.
- Tap Choose PDF or photos. Add one PDF, or all the JPG or PNG photos in page order.
- Wait. You can cancel. The file does not leave this phone.
- Read the size line, look at the preview, then download and upload that PDF on the form.
If the photos are in the wrong order, use Move up and Move down. The PDF is rebuilt on this phone.PDFUnderKB does not see the file.
Limits
- JPG and PNG photos, or one PDF. Up to 8 photos, or 8 PDF pages.
- Up to 8 MB for one file, and 24 MB altogether. Larger files are rejected so the phone does not crash.
- Password-protected PDFs are rejected. Remove the password first.
- Digitally signed PDFs are rejected. Compressing one would break the signature.
- A PDF that is already under the limit is returned as-is, so the text stays selectable. A bigger PDF is rebuilt as images. You will not be able to select the text, and form fields or digital signatures are removed.
- The readable copy keeps the long side of each page at 1,200 pixels or more. We stop there instead of turning small print into blotches. Shrink more is a separate button, and it says the text may be hard to read.
- Sizes here count 1 KB as 1,000 bytes. A file marked under 200 KB is at most 200,000 bytes, so it also fits a portal that counts 1 KB as 1,024 bytes.
- We never add empty data to inflate a file, and we never show a size smaller than the file you download.
Examples
You only have one page
One page under a 500 KB cap should look sharp, because the tool keeps the best quality that still fits. It will not make the file larger to approach 500 KB.
Common questions
Should I always pick 500 KB so the file looks better?
Only if your form allows 500 KB. A sharper file that is over the portal's limit is rejected. Match the chip to the form, then judge the preview.
Does my file get uploaded?
No. The PDF or the photos are read in this browser and the smaller PDF is built here. There is no account and no upload. Closing the tab drops the in-memory copy. The downloaded file is saved by your phone or computer.
Why can't I select the text in the new PDF?
If your PDF was already under the limit, it is returned unchanged and the text stays selectable. If it was too big, each page is rebuilt as a picture so the file can get small enough. You cannot select text in a picture, and form fields or digital signatures are not copied across. The result tells you which one you got.
What if the form still says the file is too big?
Check the number on the form, then try the next smaller chip. If the page stopped because a smaller file would be hard to read, look at the preview before you tap Shrink more. The size on screen is the real size of the download. Empty bytes are never added to fake a different size.
Will the exam or university accept this file?
This tool only changes file size. A portal can still reject a document because it is the wrong document, the wrong page count, or past a deadline. This site is not the exam body, the university, or a government office. Read the notice on your form before you submit.