Resize PDF
Resize PDF to A4, Letter, Legal — or any custom size.
Pick a page size, choose Fit, Fill, or Stretch, and download a fresh, canonical PDF — processed entirely in your browser.
Drop a PDF here, or click to browse
Resize every page to A4, Letter, Legal or a custom size
Files never uploaded
Processed entirely in your browser.
No retention
Nothing stored — nothing to delete.
Private by design
No accounts required, no tracking of your files.
Why creators choose FormatLayer
Fast, lossless processing
Preserves text, fonts, and vector graphics — no quality loss.
Works on every device
Drag, drop, and download from desktop or mobile. No installs, no plugins.
100% private by design
Everything runs locally in your browser. Your files never leave your device.
What you get with Resize PDF
- One-click A4, US Letter, US Legal, Tabloid, and A3 presets
- Custom width and height in millimetres, inches, or points
- Fit (preserve aspect ratio), Fill (crop to edges), and Stretch modes
- Live before/after preview so you see the result before exporting
- Applies to every page — or leave landscape pages untouched
- Outputs a fresh canonical PDF that opens cleanly in every reader
Why people use it
Standardize mixed-size PDFs into a single consistent page format
Prepare files for international printing (A4 in Europe, Letter in the US)
Match university, court, or government submission requirements
Fix awkward pages that came from merging documents from different sources
Keep sensitive documents on your own device — nothing is uploaded
How it works
- 1
Drop your PDF onto the page
- 2
Pick a target size (A4, Letter, Legal, or custom)
- 3
Choose Fit, Fill, or Stretch
- 4
Download the resized PDF
When to use Resize PDF
- Convert US Letter documents to A4 for European clients and printers
- Normalize a merged PDF where pages arrived in three different sizes
- Resize a design proof to exact print dimensions before sending to the press
- Match a university's submission size requirement (A4, Letter, or a custom brief size)
- Downscale oversized scanned pages to a standard archival size
- Prep a booklet or brochure at exact bleed dimensions
- Fit a landscape spreadsheet export into a portrait Letter report
- Standardize contract page sizes before applying a watermark
Who uses Resize PDF?
From classrooms to legal desks, here's how different teams put Resize PDF to work every day.
Businesses
Convert US Letter documents to A4 for international clients, partners, and print vendors.
Professionals
Normalize a merged PDF where pages arrived in mixed sizes from different sources.
Designers
Prep pages at exact dimensions for print, booklet, or brochure production with bleed.
Engineers
Standardize drawing sheet sizes for consistent plotting, review, and archiving.
Students
Match university, thesis, or coursework submission size requirements exactly.
Government Offices
Standardize scanned intake documents to a single archival page size.
Legal Professionals
Convert Letter court filings to A4 for cross-border matters and vice versa.
Print Shops
Resize customer files to the exact press dimensions before plate-making.
Publishers
Reformat manuscript PDFs to trim size before typesetting.
Pro tips
- Use Fit when you care about the whole page being visible — the safest default
- Use Fill only when a bleed edge matters more than the outer margin
- Stretch distorts geometry — reserve it for image-only pages, never text
- Resize before Watermark or Compress so the mark and compression apply to the final page size
- For print, resize to the exact target (A4 = 210×297 mm) rather than 'close enough'
- If your PDF has a mix of portrait and landscape, resize both dimensions to the largest expected page and let Fit centre each one
- Everything runs in your browser — nothing is uploaded, so it's safe for confidential, financial, and legal PDFs.
Best practices
- Keep an untouched original before resizing — it is the only way to undo cleanly
- Resize first, then Watermark, then Compress — in that order
- For print, match the printer's exact page size, including any bleed
- For archival, pick one standard (A4 or Letter) and normalize everything to it
- Test on the first two pages before batch-resizing a 200-page file
Common mistakes to avoid
- Using Stretch on a text document — letters look squashed or elongated
- Resizing after compressing — you lose quality twice
- Assuming Letter and A4 are the same — they differ by ~6 mm in width and ~18 mm in height
- Forgetting to check landscape pages — they may need a different target size
- Resizing a scanned PDF up (enlarging) — the underlying image gets softer
Everything you need to know about resizing a PDF
Resizing a PDF means changing the physical dimensions of every page — for example, from US Letter (8.5 × 11 in) to A4 (210 × 297 mm), or to a custom size for a booklet or brochure. It is one of the most requested and most misunderstood PDF operations. Done correctly, resizing standardises a document so it prints cleanly, submits to a portal successfully, or archives at a consistent size. Done wrong, it crops important content or distorts text.
FormatLayer's Resize PDF tool runs entirely in your browser. Your file is opened, resized, and re-exported on your own device using pdf-lib. No upload happens at any step. That means sensitive documents — contracts, tax filings, medical records, court exhibits — stay entirely under your control while you resize them.
This page walks through the three resize modes, the most common real-world use cases (printing, students, business, mobile), the mistakes people make, and how to combine Resize PDF with the other FormatLayer tools for a full document workflow.
Printing use cases: A4, Letter, and Legal
A4 (210 × 297 mm)
The default page size across Europe, the UK, most of Asia, Africa, and Australia. Resize to A4 before sending to a European client, printing at a European copy shop, or submitting to a UK university, government portal, or standards body.
US Letter (8.5 × 11 in)
The default in the US, Canada, Mexico, and much of Latin America. Resize to Letter for US-based printers, IRS and government forms, US court filings, and any partner that expects the North-American standard.
US Legal (8.5 × 14 in)
Common for US legal contracts, real-estate deeds, and long tabular reports. Resize to Legal to preserve wide tables and long lists without shrinking font size.
Tip for cross-border printing: A4 is 6 mm narrower and 18 mm taller than Letter. Printing a Letter-sized PDF on an A4 printer without resizing usually crops the sides or leaves an oversized bottom margin. Resize first, and the printer never has to guess.
Student workflows
Almost every university and coursework portal specifies a page size — usually A4 in Europe or Letter in North America — and rejects submissions that don't match. Students most often need to resize when combining exports from multiple tools: LaTeX outputs A4 by default, Word defaults to Letter in US installations, Google Docs varies by locale, and phone-scanned pages can be all sorts of sizes.
The reliable workflow: Merge PDF your components first, then Resize PDF to the target size the portal requires. If your merged file mixes portrait and landscape pages (a long spreadsheet inside a report, for example), pick the target size that accommodates the largest page and let Fit centre the rest.
For thesis or dissertation submissions, double-check the required margins in your institution's guide. Resize PDF changes the page size but does not touch content margins — use Crop PDF before Resize if you need to trim excess white space.
Business workflows
In business contexts, mixed page sizes are usually the symptom of a document assembled from multiple sources — a signed cover page scanned at Letter, an internal report generated at A4, an appendix pulled from a legacy system at some arbitrary custom size. Before you send that PDF to a client or archive it, normalise every page to one size with Resize PDF.
The order matters: Resize first, then Watermark PDF (so the mark lands correctly on the final page), then Compress PDF (so compression targets the final content, not soon-to-be-replaced pages). Reversing the order forces reprocessing and slowly degrades scanned pages.
For international teams, standardise on one page size per document type and stick to it. A4 is the safer default for cross-border work; Letter is the safer default for anything US-only.
Mobile workflows: resize a PDF on iPhone or Android
Resize PDF works in mobile Safari, Chrome, and Firefox with no app install. Open FormatLayer on your phone, tap the upload area, and pick a PDF from Files (iOS) or your file manager (Android). Choose your target size and tap Download; the resized file lands in your Downloads folder or Files app.
Two practical notes for mobile: keep the file under about 40 MB for smooth processing on most devices, and don't switch tabs mid-export — some mobile browsers pause background tabs and the export may stall. Everything else works exactly as on desktop.
Common problems and troubleshooting
"My content got cropped."
You resized in Fill mode. Fill scales the content to cover the new page and crops anything that overflows. Switch to Fit for a safe, non-cropping resize.
"My text looks stretched or squashed."
You resized in Stretch mode. Stretch scales width and height independently. Use Fit or Fill instead — they preserve the aspect ratio.
"My scanned PDF looks blurry after resizing."
Enlarging a scanned image beyond its original resolution softens it — there are no extra pixels to invent. Resize scanned PDFs down or leave them at their original size; if you must enlarge, rescan at a higher DPI first.
"The file won't open." / "Resize failed."
The PDF is likely password-protected. Remove the password with Unlock PDF first (you'll need the password), then resize the unlocked result.
"The tool freezes on a big file."
Your device is running low on memory for that document. Try again on desktop, close other tabs, or split the file with Split PDF, resize each part, and re-merge with Merge PDF.
"Landscape pages look wrong."
Fit centres each page regardless of orientation, so landscape pages sit centred on a portrait target with wide margins. If you want landscape pages to fill the page, pick a target size that matches or use Rotate PDF to make orientation consistent first.
Professional tips
- Match the printer's exact page size, including any bleed. "Close enough" costs you a reprint.
- For archival, pick one standard (A4 or Letter) and normalise every incoming document to it — even the ones you think are already the right size.
- Test on the first two pages of a long document before committing to a batch resize.
- If your PDF mixes portrait and landscape, resize to the target that fits the largest page and let Fit centre everything else.
- For legal and financial filings, verify page count is unchanged after resizing.
Common mistakes to avoid
- Using Stretch on documents with text — letters end up visibly distorted.
- Compressing first and then resizing — you lose quality twice.
- Assuming A4 and Letter are the same. They differ by about 6 mm × 18 mm.
- Enlarging a scanned PDF hoping for higher resolution — enlarging cannot add detail.
- Skipping a backup of the original before resizing a critical document.
How Resize PDF handles privacy
Your PDF is read directly from your device into your browser tab using the standard File API. All resizing — page rebuilding, content scaling, and re-encoding — happens locally in a WebAssembly runtime using pdf-lib. When you click Download, the finished PDF is generated in memory and handed back to your browser as a normal file save. No FormatLayer server receives, stores, or logs the contents of your file at any point.
You can verify this yourself: open your browser's Developer Tools, switch to the Network panel, and use the Resize tool. You will not see a file-upload request — because there isn't one. Full details are on the Security and Privacy pages.
Continue reading
Guides that pair well with Resize PDF — from choosing a page size to combining Resize with the rest of your PDF workflow.