Resize PDF not working? Find your symptom, get the fix

Your symptom, the cause, the fix

Resize PDF does two different jobs, and most of the confusion comes from mixing them up. Choose File size when a form gives you a number like 100 KB. Choose Page size when you need a paper size like A4. The next section is the most common mix-up.

"I changed to A4, but the file is just as big"

That is expected. Page size is the size of the paper, like A4 or Letter. File size is the room the file takes, in KB or MB. They are separate. When you change the page size, every page is scaled to fit the new paper, but the pictures inside stay as they are. So the file stays about the same size.

To make the file smaller too, do the page size first and then the file size:

1. Choose Page size, pick A4, add your PDF and download the A4 copy.
2. Choose File size, pick your limit, and add the A4 copy.
3. Upload the file whose name ends in A4 and your size, like marksheet-A4-100KB.pdf.

Do them in this order because the size limit is checked on the file you upload. Changing the page size afterwards could change the file again. In our tests, a 14-page Letter paper became A4 in 0.4 seconds, so the first step is quick. The post Change PDF page size to A4 has the full steps.

"The result says Over my size"

Over means the file can't get any smaller, and what you got is the smallest version possible. It nearly always happens with typed PDFs, not scans. A scan is a set of pictures, and pictures can always be made smaller. A typed PDF is mostly text, fonts and drawings, which we copy exactly as they are so that words stay sharp and searchable.

Two of our own files show it. A 14-page research paper of 992 KB could go to 766 KB and fitted under 1 MB with Sharp pictures. A 117-page maths textbook of 5.07 MB could not go below 2.56 MB, and under 1 MB it was Over, with Rough pictures. In both, the weight was text and drawings, not pictures.

What to try, from the easiest:

• Send only the pages the form asks for. Every page shares one limit, so each page you leave out gives the rest more room. This works for every PDF, text-heavy ones too. Split PDF saves just the pages you pick.
• Ask for a bigger limit, or for separate uploads.
• For a page or two, try the picture trick. Turn the page into a picture with PDF to JPG, put it back into a PDF with JPG to PDF, then resize. The 200 KB guide shows it working on a one-page typed file: 302 KB became 167 KB and Sharp. The words are no longer searchable. It doesn't suit long documents: on 14 pages it went Rough.

Typed PDF over 200 KB? Why it won't shrink and how to fix goes through the options in detail.

"It fits, but the pages look blurry"

Every result carries one word about the pictures: Sharp (150 ppi and up), Good (100 to 149), Readable (45 to 99) or Rough (under 45). The word comes from the pixels per inch the pictures kept. If you see Rough, or Readable near the bottom of its band, the pages had too little room.

The room each page gets is the limit divided by the number of pages. That is why a small limit with many pages goes soft. In our tests, a four-page scan under 100 KB kept 73 ppi, Readable, and under 500 KB it was Good. Three scans joined into 14 pages went Rough at 38 ppi under 100 KB.

What helps, in order:

1. Pick a bigger size, if the form allows, then press the Redo button on the file's row, such as Redo at 200 KB (or Apply to all when you have several files). A finished file stays as it is until you do.
2. Send fewer pages. Halving the pages gives each one roughly the room of twice the limit.
3. Scan again in grayscale, if colour isn't needed. With no colour to store, more of the limit goes to sharpness.
4. Scan at 150 to 300 dpi. A higher setting only makes the file bigger and slower to resize, and doesn't make small text easier to read.
5. Crop to the paper and lay the page flat in good light. A table or a shadow in the photo takes room the words could use.
6. Start from the original scan. A copy that was already made smaller has lost detail for good, and squeezing it again loses more.

For the story of what ppi means, see What is PPI? Why scans look Sharp, Good or Readable.

"White bands appeared at the top and bottom"

When the old and new paper have different shapes, a page can't fill the sheet exactly. Stretching would distort the text, and cutting would lose part of the page. So the page is scaled to fit and centred, and the leftover shows as white. Letter is a little wider and shorter than A4, so a Letter page becomes about 97% of its size to fit A4's width, leaving about 13 mm of white at the top and bottom. Going from A4 to Letter works the other way round, with the margins at the left and right.

Nothing is cut off, and text stays text, so it is sharp and searchable. Links, form fields, comments and bookmarks move with the page and keep working. A4, A3 and A5 share one shape, so between them a page just gets bigger or smaller and fills the sheet.

If you don't want the margins, the only way is to use the paper the page was made for. For printing, the sizes of paper and the choices in the print window matter more than the white bands: pick Actual size when the PDF matches the paper, and Fit to page when it doesn't.

"The form still says my file is too big"

Go through these, in this order:

• Is it the right file? The original and the resized copy sit side by side in your Downloads. The resized one has the size at the end of its name, like scan-100KB.pdf. It is easy to pick the original by mistake.
• How does the form count? We count 1 KB as 1,000 bytes. A file under 100 KB here is under 100 KB on every website, even those that count 1,024 bytes. If your file manager shows a number above the limit, check that it counts the same way. How big is 100 KB? explains the two ways to count.
• Did the limit change? Forms change their rules from year to year. Read the notice again.
• Is the limit for the whole upload? Some forms add up all the files. Then each file has less room.
• Did you resize the right size? If you picked 200 KB and the form wants 100 KB, the file is too big for it. The result's name tells you which size you picked.

"The tool won't take my PDF"

A PDF that needs a password to open can't be resized as it is, because the tool can't read what is inside it. Remove the password first with Unlock PDF, which needs the password, and then resize the unlocked copy. Bank statements and e-Aadhaar PDFs are often locked this way. The post Remove password from a bank statement PDF shows how.

Two other cases. A PDF with a digital signature loses the signature's validity when it is changed, so keep the original for anything that needs it signed. And a file that is damaged or not really a PDF can't be opened at all: try to open it in a viewer to see.

"It is slow, or my phone struggles"

To hit a size, the page makes the file, measures it and tries again, up to six tries. Each try is a full pass over the file, so big files take longer. In our tests, scans up to 10 MB took 1 to 5 seconds, and a 47.8 MB scan took 37 seconds to fit under 2 MB. These times come from our own tests, run in headless Chromium. In general, the tools are tested through our independent tests and our agentic testing workflow, in headless Chromium at phone and computer sizes, and these tests don't cover Safari or Firefox. A phone may be slower than our test computer.

• Keep the page open and in front until the result appears.
• Close other tabs if the phone is short of memory.
• Resize fewer files at a time. They are done one after another, so a long list takes a while.
• Be patient with the biggest scans. More pages and more pixels mean more work for each try.

Your files stay on your device

Resize PDF has no upload step and never sends your file anywhere. It runs inside your browser, on your phone or computer. The page contacts only this site and Google's ad service, which shows the ads that keep the tools free. Our code never gives your files to the ad code. The privacy policy has the details.