Resize PDF to the size you need

Two kinds of resizing

When people say "resize a PDF", they mean one of two things, and this tool does both:

• File size: how much space the file takes, in KB or MB. Upload forms care about this, as in "PDF under 100 KB". This is what most people need.
• Page size: the size of the paper, like A4 or Letter. Printers and some offices care about this.

The two are separate. Making a PDF smaller in KB keeps every page the same size on paper, and changing the paper size keeps the file about as big as it was. Choose File size or Page size at the top of this page.

Why forms ask for 100 KB or 200 KB

Job, exam, admission, scholarship, bank and government websites often accept a PDF only under a set size, such as 50 KB, 100 KB, 200 KB, 500 KB or 2 MB. The limit keeps their servers fast when thousands of people apply at once.

Scans are much bigger than that. Our sample file, a 4-page scan at 300 pixels per inch like an office scanner makes, is 9.96 MB: about 2.5 MB a page. Photos from a phone camera are often several MB each. A file even slightly over the limit is usually refused, sometimes after you have filled in the whole form.

NoUploadPDF makes the file fit and keeps it as clear as the limit allows, so the person on the other side can still read every word.

How the size finder works

Hitting an exact size is harder than it sounds, because nobody can tell in advance how small a PDF will get. So the resizer tries, measures and adjusts:

1. First try. It makes the file with our Recommended setting, which keeps pictures at 150 pixels per inch.
2. Find the edges. If that is still too big, it tries the strongest setting to see how small the file can get. If it already fits, it tries the gentlest setting to see whether full quality fits too.
3. Close in. Each next try aims between the closest result that fits and the closest that doesn't, until one lands just under your size, within 15% of it.
4. Keep the best. You get the sharpest version that fits, after six tries at most.

Only pictures change. Text, fonts, lines and drawings are copied as they are, so words stay sharp and searchable at any size. For pictures, each step lowers the sharpness (from 220 down to 30 pixels per inch) and the JPEG quality (from 85 down to 15) a little at a time.

We count 1 KB as 1,000 bytes, so a file under 100 KB here is also under 100 KB on websites that count 1 KB as 1,024 bytes.

Real results

We resized these files in Google Chrome on our test computer. "Your size" is the limit we picked, and "After" is the file the resizer made. Times on your device may be shorter or longer.

• 91 KBfrom a 9.96 MB scan, for a 100 KB limit
• 2 to 5tries to land just under your size
• 1 to 5 sfor scans up to 10 MB
• 0 bytessent to any server

Scans fit even small limits, because they are made of pictures. Text-heavy PDFs are different: the 14-page paper fit under 1 MB at full picture quality, but the 117-page textbook can't go below 2.56 MB, because most of it is text and drawings, which we keep sharp. When that happens, the result says so, and you still get the smallest version.

It is light on your device, too. Resizing the 6.37 MB scan needed 65 MB of memory and one processor core for four seconds, and the memory was handed back as soon as the file was done.

How sharp it stays

Every result tells you in one word how sharp the pictures stayed. The word comes from the pixels per inch (ppi) the pictures kept:

In our tests, normal-sized text in a scan could still be read at 48 ppi, though it looked soft, and read easily at 57 ppi. If you see Rough and the website allows a bigger file, pick a bigger size: your file is done again straight away.

Changing the page size

Choose Page size to give every page the same paper size. Each page is scaled to fill the new paper as far as its shape allows and centred on it, so nothing is cut off. When the shapes differ, for example Letter to A4, a thin white margin appears on two sides.

• Links, form fields, comments and bookmarks move with the page and keep working.
• Text stays text. It is scaled, not turned into a picture, so it stays sharp and searchable.
• Pictures stay as they are, so the file stays about the same size.
• Direction: "As it is" keeps each page upright or sideways as it was; Portrait or Landscape turns every page the same way.

In our tests, a 14-page Letter paper became A4 in 0.4 seconds, and a 117-page A4 textbook became Letter in 3.9 seconds. Pages that already have the size you pick are left as they are.

Tips for a small PDF

1. Scan in grayscale. Forms, marksheets and letters rarely need colour. At 100 KB, our grayscale scan kept sharper pictures (57 ppi) than the colour one (48 ppi).
2. Send only the pages asked for. Every page shares the same limit, so fewer pages leave more room for each one.
3. Scan at 150 to 300 dpi. Higher settings make huge files without making text easier to read.
4. Start from the original. A file that was already squeezed has lost detail you can't get back.
5. Check before you upload. Open the new file and zoom in on the small print. If it isn't clear enough and the website allows more, pick a bigger size.

Resize PDFs on Android, iPhone, Windows and Mac

The resizer runs in your web browser, so there is nothing to install: no app, no extension and no account. It works the same way on phones, tablets and computers.

• Android

  Open this page in Chrome, Samsung Internet or another up-to-date browser. Tap "Choose PDF files", pick your PDF and choose a size. The new file is saved to your Downloads folder, ready to upload.

• iPhone and iPad

  Open this page in Safari or Chrome, tap "Choose PDF files" and pick a PDF from the Files app. The new file usually goes to Downloads in the Files app.

• Windows, Mac, Linux, Chromebook

  Use Chrome, Edge, Firefox or Safari, and drop one or many PDFs onto the page. The new files go to your Downloads folder.

You can add several PDFs at once. They are resized one after another, each gets its own Download button, and if you pick another size, all of them are done again at the new size.

KB, MB, ppi and paper terms, explained

KB (kilobyte)

A measure of file size. We count 1 KB as 1,000 bytes, so "under 100 KB" means 100,000 bytes or less, which fits every website's limit.

MB (megabyte)

1,000 KB. A 2 MB limit is twenty times bigger than a 100 KB one, so pictures can stay much sharper.

PPI (pixels per inch)

How many picture dots fill one inch of the page. More pixels per inch means a sharper picture and a bigger file.

DPI (dots per inch)

The resolution setting on a scanner or printer. A page scanned at 300 dpi becomes a 300 ppi picture inside the PDF.

Portrait and landscape

A portrait page stands upright, taller than it is wide. A landscape page lies sideways, wider than it is tall.

Scale to fit

Making a page bigger or smaller without changing its shape, so that all of it fits on the new paper. Nothing is cut off.

Private by design

Forms ask for your most private papers: Aadhaar and PAN cards, marksheets, certificates and bank statements. With NoUploadPDF they never leave your device. The resizer runs inside your browser, the page is not allowed to send data to any other website, and it keeps working with the internet switched off once the page has loaded.

You can check this yourself in your browser's network panel: nothing is uploaded. Our guide to private compression explains how the protection works.

Limits

• PDFs that need a password to open can't be resized yet. Remove the password in your PDF reader first.
• A PDF with a digital signature loses the signature's validity when it is changed.
• Text, fonts and drawings set a smallest size, so a long text document may not fit a very small limit.
• A small limit for a scan with many pages leaves little room for each page, so pictures get rough.
• Big files take longer, because each try is a full pass over the file: our 47.8 MB scan took 37 seconds to fit under 2 MB.
• Changing the page size doesn't make a file smaller. To do both, change the page size first, then make the new file smaller.