How to Resize PDF Pages Online
Change PDF page size in three simple steps. No software installation required.
Add Your PDFs
Select one or more PDF files, or drop them into the tool.
Choose the New Page Size
Choose a paper size such as A4 or Letter, then set how the content fits and the image resolution.
Resize and Download
Click “Resize PDF,” preview the result, then download each PDF or all completed files as a ZIP.
How Does the PDF Resizer Work?
The CompressFly PDF resizer changes your document's page size to A4, Letter, or another supported paper size. Scale large pages down, enlarge smaller pages, or give a mixed-size document a consistent page size. Embedded images are optimized at the selected resolution; the PDF is not converted into a series of page images. Resize files individually or in a batch, then preview the results before downloading. Your PDFs are processed locally in your browser instead of being uploaded to a server. Free to use, with no signup required.
What "processed locally" means
- Your PDFs are not uploaded to a server
- Page resizing happens on your device
- Embedded images are processed in your browser
- New PDF copies are created locally for download
Fit PDF Content to a New Page Size
When the original and new page sizes have different proportions, the fitting mode changes how the content appears. If you only want to trim margins, use Crop PDF instead.
| Mode | How the content fits | What to expect |
|---|---|---|
| Fit | Keeps the whole page in proportion | Extra space may appear along the edges |
| Fill | Fills the new page without changing proportions | Content near the edges may be cropped |
| Stretch | Matches the new page's width and height | Text and images may look stretched or squeezed |
Page fitting controls layout, not image quality. Embedded images are processed separately using the selected resolution preset.
Why Use CompressFly to Resize PDF Pages?
Easy to Use
Prepare a PDF for a different page size without learning a layout application. The resizer keeps a routine document adjustment straightforward.
Less Layout Work
A document can be adapted to familiar paper sizes without rebuilding its contents. This is helpful when mixed-size pages need a more consistent presentation.
No downloads required
Make the resized copy in your browser instead of installing a desktop editor. A simple page-size change does not need a full publishing workflow.
Built-in Preview
Changing page dimensions can affect how a document looks. The included preview gives you a chance to judge the finished copy before using it for sharing or printing.
Free to Use
Adapt your document without buying a PDF subscription. No account or payment details are required to use the resizer and keep the result.
Local Document Handling
The source PDF stays on your device while the new copy is created. Page resizing runs in the browser without uploading your files for processing.
Related PDF Tools
Resize PDF FAQ
How do I change PDF page size online?
Resize your PDF in three steps: 1. Add one or more PDF files. 2. Choose a paper size, fitting mode, and image resolution. 3. Click “Resize PDF,” then preview and download the result.
Which PDF page sizes are supported?
You can resize PDF pages to A3, A4, A5, US Letter, Legal, or Tabloid (11 × 17 inches). Choose A4 to convert a Letter PDF to A4, or Letter for the reverse. Custom width and height are not available on this page.
Can I resize only selected PDF pages?
This page applies the same settings to every page of each PDF. To work with a selected page or section, save it first with Extract PDF Pages, then resize that file.
Does resizing a PDF reduce its file size?
Not necessarily. Changing page dimensions is different from reducing file size. The image presets can make image-heavy PDFs smaller, but the result is not guaranteed to be smaller or meet a KB or MB target. Use Compress PDF when file-size reduction is your main goal.
Will resizing a PDF reduce image quality?
It can. Lower-resolution presets can reduce detail in embedded images. High and High+ both use a 300 DPI limit, but High+ uses a higher quality setting. Higher DPI does not restore missing image detail, and neither option guarantees lossless output.
What happens if I choose “Keep unchanged”?
Your pages keep their original dimensions. Embedded images are still processed using the selected resolution preset, so the file can change even though its paper size does not.
Can I resize multiple PDFs to the same paper size?
Yes. Add several PDFs and apply the same paper size, fitting mode, and image preset to all of them. Each PDF is saved separately, not merged. Download the results individually or together in a ZIP.
Is this PDF resizer free, and are my files uploaded?
Yes, it is free, with no registration or credit card required. Your PDFs are processed locally in your browser, and new copies are created on your device. Your files are not uploaded to a server, and the originals stay unchanged.