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How to change the size of a PDF
Two different things are called "PDF size." To change the page size (A4, Letter, Legal), use the Resize tool. To make the file smaller in MB, use Compress. Both are free and run in your browser.
No upload. Your PDF is processed in your browser, not on our servers.
How do I change the size of a PDF?
It depends what you mean by "size." To change the page dimensions — for example A4 to US Letter — open RaptorPDF's Resize tool, drop in your PDF, pick a preset (A4, Letter, Legal) or a custom size, click Resize, and download.
To reduce the file size in megabytes so it's small enough to email or upload, use the Compress tool instead. Both are free, add no watermark, and process the file in your browser — nothing is uploaded to a server.
Which one do you need?
Pick the goal that matches what you're trying to do.
Change page size
The pages are the wrong dimensions — you need A4, Letter, Legal or a custom size. Common for printing and standardising documents.
Open Resize PDF → ▼Reduce file size (MB)
The PDF is too big to email or upload. Compress shrinks the megabytes while keeping readable quality.
Open Compress PDF →Change page size: A4, Letter or custom
Four steps — no account needed to start.
Open the Resize tool
Go to Resize PDF and drag in your file, or pick one from your device.
Choose the new size
Pick A4, Letter or Legal, or enter a custom width and height.
Set a fit mode
Choose Fit, Fill or Stretch to control how the content scales to the new page.
Resize & download
Click Resize and save the file. No watermark on your PDF.
Page size vs file size
| Page size | File size | |
|---|---|---|
| What it means | Physical page dimensions | Storage the PDF uses |
| Measured in | A4, Letter, mm, inches | KB / MB |
| You want this when | Printing, standardising layout | Emailing, uploading, attachments |
| Use this tool | Resize PDF | Compress PDF |
Common conversions
A4 to US Letter (and back)
A4 (210×297mm) is standard in most of the world; US Letter (8.5×11in) is standard in the US and Canada. To convert, open the Resize tool, choose the target preset, and resize. Using a fit mode keeps your content centred and correctly scaled on the new page.
Make a PDF smaller for email
If an attachment is rejected for being too large, run it through Compress. This reduces the megabytes without changing the page dimensions, so the document still looks the same — it just takes up less space.
Frequently asked questions
How do I change the size of a PDF?
It depends what you mean by size. To change the page size (dimensions, such as A4 to Letter), use RaptorPDF's Resize tool: open it, drop in your PDF, choose a preset or custom size, click Resize, and download. To change the file size (megabytes), use the Compress tool. Both run in your browser with no signup.
How do I change a PDF from A4 to Letter size?
Open the RaptorPDF Resize tool, drag in your PDF, choose the Letter preset (or A4 the other way), then click Resize and download. Every page is changed, and the file is processed in your browser — not uploaded.
What is the difference between page size and file size?
Page size is the physical dimensions of each page — for example A4 (210×297mm) or US Letter (8.5×11in). File size is how much storage the PDF uses, in KB or MB. Use Resize for page size and Compress for file size.
How do I make a PDF file smaller in MB?
Use RaptorPDF's Compress tool. Open it, add your PDF, and download the compressed version. It reduces the file size while keeping readable quality — useful when a PDF is too large to email or upload.
Is it free to change PDF size online?
Yes. Changing a PDF's page size or file size with RaptorPDF is free, works in your browser, and adds no watermark. No account is required to start; free users can download up to 3 files per day.
Will changing the page size affect quality?
Resizing changes the page dimensions and scales the content to fit. Text and vector graphics stay sharp because they aren't rasterised. A fit mode (Fit, Fill or Stretch) controls how content scales to the new page size.
Change your PDF size now
Resize the pages or shrink the file — free, in your browser, no signup to start.
Open Resize PDF