About the Resize PDF
Resize PDF puts every page of your document onto a page of a different size. Pick A3, A4, A5, A6, Letter, Legal, Tabloid or type a custom width and height in millimetres, choose portrait, landscape or the same orientation as each page, and decide whether the old page should fit inside, fill the new page or be stretched. The old page is scaled as one block, so text is not reflowed and gets bigger or smaller with the page. This changes the page dimensions, not the file size, and it runs in your browser.
Updated September 2026
How to use the Resize PDF
- 1Select the PDF you want to resize.
- 2Choose the New page size, or pick Custom and enter millimetres.
- 3Set the orientation and how the old page should fit: Fit inside, Fill or Stretch.
- 4Resize all pages, or choose Only some pages and list them, like 1, 3-5.
- 5Click Resize PDF, then Download PDF.
Common page sizes
Most of the world uses the A series: A4 is 210 × 297 mm, A3 is double that area, and A5 is half. The United States and Canada use Letter (215.9 × 279.4 mm) and Legal (215.9 × 355.6 mm), while Tabloid is 279.4 × 431.8 mm.
A document made for one system often prints with odd margins on the other, which is the usual reason to convert. Pick the size your printer or recipient expects, and check the live line that shows the old and new dimensions in millimetres.
Fit, fill or stretch
Fit inside is the safe default: the whole page stays visible and is centred. Fill suits a page that has bleed or a background you are happy to trim. Stretch is useful only when the shapes are almost the same, for example A4 to Letter, where the distortion is small.
- Fit inside: nothing lost, possible empty margins.
- Fill (crops edges): no margins, some content cut off.
- Stretch: no margins and nothing cut, but shapes look squeezed.
Printing a PDF made for another paper size
Print dialogs offer Fit to page, but the result depends on the printer driver and is hard to check beforehand. Converting the file first gives you a preview you can trust and a PDF you can send to anyone.
If some pages are scans of different sizes, resize the whole document to one size so it prints and reads consistently. Combine documents with Merge PDF afterwards.
Limits: links and forms
Because pages are drawn again on new pages, clickable links, form fields and bookmarks may stop working in the result. If you need a filled form to stay usable, keep the original size, or flatten it with Flatten PDF.
Pages stored with a built-in turn (a rotation flag inside the file) are copied without resizing, and the tool tells you how many there are. For a smaller file, use Compress PDF.
Features
- A3, A4, A5, A6, Letter, Legal and Tabloid
- Custom size in millimetres
- Portrait, landscape or matched to each page
- Fit inside, Fill or Stretch
- Resize only the pages you choose
- Live sizes in millimetres before you start
- Private: the PDF stays on your device
Frequently asked questions
How do I change a PDF to A4?
Open the PDF here, leave the size on A4, keep Fit inside and click Resize PDF. Every page is placed on an A4 page, centred and scaled so nothing is cut off. The download is named with -A4 at the end.
Will the text be resized?
Yes, along with everything else on the page. The tool scales the page as a picture-like block rather than re-flowing paragraphs, so shrinking a page to A5 makes the text smaller and enlarging it to A3 makes it bigger.
What is the difference between fit and fill?
Fit inside keeps the whole old page visible and may leave empty margins when the shapes differ. Fill covers the entire new page and cuts off whatever sticks out. Stretch forces the old page into the new shape and can distort it.
Does resizing reduce the file size?
No. Page size and file size are different things, and a smaller page does not mean a smaller file. To shrink the file itself, use Compress PDF after resizing.
Can I resize only some pages?
Yes. Choose Only some pages and type numbers or ranges such as 2, 5-7. Those pages get the new size, and every other page is copied over unchanged.
What size is US Letter in mm?
US Letter is 8.5 by 11 inches, which is 215.9 by 279.4 millimetres. It is slightly wider and shorter than A4, which measures 210 by 297 millimetres.