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How to Change the Page Size of a PDF (A4 to Letter)

Change a PDF from A4 to Letter or Letter to A4 for free — set the paper size in your browser's print dialog, or trim custom sizes with a crop tool.

HM

Hamza M.

PDF Workflow Editor

September 22, 20263 min readReviewed September 22, 2026

A PDF keeps the page size it was created with, but that size is not fixed forever — you can change it afterwards. Around half the people asking how to change the page size actually mean one of two different things: matching a PDF to a standard paper size (A4 to Letter, Letter to A4), or trimming a PDF down to a custom size. The fix differs, so check which one you need first.

Which method is yours?

What you wantFastest methodWhere it runs
A4 to Letter, or any two standard sizesBrowser print dialog, paper-size settingBuilt into Chrome, Edge, Safari
Trim margins or shrink an irregular pageCrop the page edgesCrop PDF tool
Every page the same size in a mixed documentPrint the whole file to one standard sizeBuilt into your browser

Change A4 to Letter (or back) with the print dialog

Every browser can save a PDF to a chosen paper size, and most operating systems can too. In Chrome and Edge the setting sits in the print dialog, and it re-sizes the actual PDF file, not just the printout.

  1. 1Open the PDF in your browser.
  2. 2Press Ctrl+P on Windows or Cmd+P on Mac.
  3. 3Set the destination to "Save as PDF".
  4. 4In More settings, choose the paper size — Letter, A4, or another standard.
  5. 5Choose Scale: Fit to page so content re-flows to the new size, then Save.
  6. 6Open the new file to confirm the pages are the size you chose.

Trim a page to a custom size with the crop tool

When the goal is removing an uneven white border — a scanned page with ragged edges, or a slide exported with a wide frame — the Crop PDF tool adjusts the margins directly, shrinking the page to the content you want to keep.

  1. 1Open the Crop PDF tool and add your file.
  2. 2Adjust the margins on each side until the page is the size you want.
  3. 3Apply the crop and download the trimmed PDF.
  • Crop trims inward only — it never grows a page, so use the print dialog when you need to scale content up
  • For a book-style scan, crop the outer edges first, then unify the odd page with a print pass
  • Keep the original if you might need the un-trimmed version later

Standard sizes by region

SizeDimensionsWhere it dominates
A4210 × 297 mmMost of the world outside North America
Letter8.5 × 11 in (216 × 279 mm)US and Canada
Legal8.5 × 14 in (216 × 356 mm)US legal documents

Fixing mixed-size documents

A file where a few pages differ from the rest — common after scanning a document that combined two paper stocks — is best handled in one pass: print the whole PDF to the single target size so every page standardizes together, rather than cropping page by page.

Do it now

Crop PDF

Crop and resize PDF pages. It runs in this browser tab — your file is not uploaded anywhere.

Open Crop PDF

Frequently asked questions

Can I change a PDF to A4 without installing software?+

Yes. Open the PDF in a browser, use the print dialog with the destination set to "Save as PDF", pick A4 from the paper-size options, and save — no software to install.

Does changing the page size shrink the text?+

The "Fit to page" scale option resizes content to fill the new page, so an A4-to-Letter change re-flows text rather than cropping it. Check tables and images after saving.

Can I make a PDF page larger than its content?+

Yes, with the print dialog — choose a larger paper size and a scale above 100%. The crop tool only trims inward, so it cannot grow a page.

What if my PDF has pages of different sizes?+

Print the whole file to one target standard size so all pages normalize together. Cropping outliers one at a time leaves the document inconsistent.

Do form fields survive a page-size change?+

Usually not — printing to PDF flattens fillable fields to their current values. Keep the original if you still need an editable form.

Keep reading

HM

Hamza M. · PDF Workflow Editor

Hamza has spent a decade working with print and digital documents — from prepress production to everyday PDF cleanup — and now writes practical, tested guides for Slate PDF.

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