Change PDF Page Size to A4, Letter, or a Custom Dimension
Printers reject documents, submission portals complain, and readers show awkward margins when a PDF was built for the wrong page size. The Page Size Converter rescales every page of a PDF to a standard format such as A4, Letter, Legal, or A5, and it also accepts a fully custom width and height. The geometry of the content itself stays intact while the page canvas is adjusted, so text and images are not redrawn or reflowed. You get a print-ready file in seconds, without installing a desktop editor.
How to Convert the Page Size of a PDF
- Open the Page Size Converter and upload the PDF you need to resize; drag and drop works for quick access.
- Choose a preset like
A4,Letter,Legal, orA5, or type a custom width and height in points or millimeters. - Pick a fit mode:
containkeeps the whole page visible inside the new canvas, whilestretchscales the content to fill it completely. - Set the background color that fills any empty margin left by the contain mode.
- Click convert, preview the first page, and download the resized PDF.
Real Example: Fitting a Letter Document for A4 Printing
A contract drafted in the United States is Letter-sized, but the office printer in Europe loads A4 paper. Converting with the A4 preset and contain mode adds thin side margins instead of cropping the signature block, so the whole document prints without anything cut off. A quick preview confirms the layout before you send it to the printer.
| Input | Output |
|---|---|
contract.pdf at Letter (612 x 792 pt) | contract-a4.pdf at A4 (595 x 842 pt) |
Fit mode contain, white background | full content preserved with even side margins |
Tips for Clean Page Size Conversion
- Use contain for contracts and forms — stretching official documents distorts signatures and makes them look altered.
- Pick the preset, not custom numbers — A4 and Letter match real paper, so printing comes out edge to edge.
- Check the preview page — one glance tells you whether the margins look balanced before you commit.
- Set a neutral background — white keeps the file printable; colored backgrounds consume toner and confuse scanners.
- Resize after merging, not before — normalize the size of a combined PDF in a single pass instead of converting each source file.
When a Page Size Change Is Needed
- International printing — switch Letter documents to A4, or the reverse, when the paper stock changes.
- Submission portals — many government and academic systems enforce an exact page dimension.
- Binding and booklets — A5 pages fold into booklets with the correct margins when trimmed.
- Unified archives — standardize a folder of mixed-size PDFs so they print and read consistently.
- Digital signage — resize presentation PDFs to match the aspect ratio of a wall display.
Frequently Asked Questions
What page size presets are available?
The tool offers A4, Letter, Legal, and A5 presets. If you need another format, enter a custom width and height in points or millimeters instead.
What is the difference between contain and stretch?
Contain fits the existing page inside the new canvas, adding background-colored margins when the aspect ratios differ. Stretch scales the content to fill the whole page, which can distort proportions.
Will the conversion change my text or layout?
No. The tool adjusts the page canvas and scales the existing content; it does not reflow text, move images, or re-render fonts. The visual structure of each page is preserved.
Can I convert every page or just some of them?
Every page in the uploaded PDF is resized in one pass. To convert only selected pages, extract them first with the page extraction tool and then resize the smaller file.
What units can I use for a custom size?
Custom dimensions can be entered in points or millimeters, which cover the units used by most print workflows. The tool converts them internally to the PDF coordinate system.
Does resizing reduce the quality of the PDF?
No. Page size conversion works on the vector content of the PDF, so text and line art stay crisp. Bitmap images inside the file are unchanged unless they are stretched.
Why does my file get extra white margins after conversion?
That happens in contain mode when the source aspect ratio differs from the target. The extra space is the background color filling the difference so nothing is cropped.
Can I convert a password-protected PDF?
Unlock the PDF first with the unlock tool, then upload the unprotected copy. The converter needs full read access to rebuild every page at the new size.