Resize PDF to A4 Free Online — Convert Any PDF to A4 Page Size

A4 is the most widely used paper size on the planet — standard in over 200 countries. If your PDF is currently Letter, Legal, A3, or some other size and you need it in A4, you can convert it free in about 5 seconds with no upload and no signup.

This is especially common when sending documents internationally. You wrote something on US Letter paper, now a European client or university needs it in A4. Or you received an oddly sized scan and need to standardize it. Either way, the fix takes three clicks.

Convert Any PDF to A4 in 3 Steps

1. Open the tool: Go to the Stork PDF Resizer and drag your PDF onto the page. The tool reads the current page size — you will see something like "Current: 612 x 792 pt (Letter)" or "Current: 612 x 1008 pt (Legal)".

2. Select A4: Click the "A4" button in the size grid. A4 is already the default selection, so if you just dropped your file and A4 is highlighted, you are ready to go.

3. Click Resize: Hit the green "Resize PDF" button. Every page in the document scales to 595 x 842 points (210 x 297 mm). The resized file downloads automatically.

The conversion preserves all content — text, images, form fields, and hyperlinks scale proportionally to fit the A4 frame.

Letter vs A4: The Actual Differences (and Why They Break Things)

Letter and A4 look almost the same at a glance. They are not. Here is the exact comparison:

Attribute	US Letter	A4
Dimensions (mm)	216 x 279	210 x 297
Dimensions (inches)	8.5 x 11	8.27 x 11.69
Width difference	Letter is 6mm wider
Height difference	A4 is 18mm taller
Used in	USA, Canada, Mexico	200+ countries worldwide

Letter is wider but shorter. A4 is narrower but taller. When you print a Letter PDF on an A4 printer without resizing first, the printer either shrinks everything to fit (leaving white bars top and bottom) or clips the sides. Neither is acceptable for professional documents.

The real-world impact: a Letter-sized resume printed on A4 paper has uneven margins. A legal contract with signatures near the bottom edge may lose the signature line entirely. Government forms that validate dimensions will reject mismatched sizes outright.

Sell Custom Apparel — We Handle Printing & Free Shipping

Who Needs A4 Conversion Most

International business: If your company has European, Asian, or Australian clients, every PDF you send should be A4. Sending Letter-sized documents signals unfamiliarity with international standards — a small thing that makes a big impression.

Students applying abroad: University applications in Europe, the UK, and Australia expect A4. Transcripts and recommendation letters from American schools are almost always Letter. Converting before submission avoids the "your document does not meet formatting requirements" rejection email.

Immigration and visa applications: Government portals worldwide specify A4. USCIS forms use Letter; most other countries use A4. If you are filing paperwork internationally, you will resize PDFs constantly.

Self-publishers: Kindle Direct Publishing and other platforms accept A4-formatted PDFs for interior pages. If your manuscript was typeset in Letter, converting to A4 ensures proper margins and gutter alignment.

Need to go the other direction — A4 to Letter? The same tool handles that conversion. Just select "Letter" instead of "A4" in step 2.

Converting to A4 From Other Sizes

Letter to A4 is the most common conversion, but the tool handles any source size:

• Legal (8.5 x 14 in) to A4: Legal pages are significantly taller than A4. Content will scale down to fit, so text will appear slightly smaller. For long legal documents, consider whether the reduced text size is still readable. If not, you may want to split the document first and then resize.
• A3 (297 x 420 mm) to A4: A3 is exactly double A4. Content scales down by 50% — text that was 12pt becomes 6pt equivalent. This works for diagrams and posters but may make body text too small to read comfortably.
• A5 (148 x 210 mm) to A4: A5 is half of A4. Content scales up by 200%. Text gets bigger, which is usually fine. Embedded images may appear slightly softer if they were low resolution to begin with.
• Custom or non-standard sizes: Scanned documents often have irregular dimensions (like 8.3 x 11.4 inches). These convert to A4 without any special steps — drop, select A4, resize.

A4 Landscape vs A4 Portrait

A4 portrait is 210 x 297 mm (width x height). A4 landscape is 297 x 210 mm — same paper, rotated 90 degrees. If your PDF has landscape pages and you resize to A4, the tool preserves proportions but fits the content into portrait A4 by default.

If you need to keep a landscape orientation while converting to A4 dimensions, use the custom option: enter 842 for width and 595 for height (the A4 dimensions flipped). This gives you A4-landscape pages.

Some documents mix portrait and landscape pages. The resizer converts all pages to the same target size. If you need different orientations for different pages, split the PDF into two groups, resize each group separately, then merge them back.

For documents that just need their pages rotated (not resized), the PDF Rotate tool handles that without changing any dimensions.

Frequently Asked Questions

Is A4 bigger or smaller than Letter?

A4 is narrower (6mm less wide) but taller (18mm taller) than US Letter. The total area is almost identical — A4 is 623.7 sq cm vs Letter 623.2 sq cm. The difference is in the proportions, not the overall size.

Will my text be smaller after converting Letter to A4?

Barely. Because the sizes are so similar, the text scale change is under 3%. A 12pt font on Letter appears as roughly 11.7pt on A4 — visually indistinguishable to most readers.

Can I convert a scanned PDF to A4?

Yes. Scanned PDFs are just images embedded in a PDF container. The tool resizes the page and scales the embedded scan to fit A4 dimensions. For better results with scanned documents, you can also run them through the PDF OCR tool first to extract searchable text.

Does this work on a phone?

Yes. The tool runs in any modern browser — Safari on iPhone, Chrome on Android, or any mobile browser. Just tap to select your file instead of dragging.