Convert PDF to A4
Resize a PDF to A4 (210 × 297 mm) online free: Letter, Legal, Long bond or mixed-size pages become uniform A4 with content scaled to fit. No upload.
About Convert PDF to A4
Many PDFs from the US are Letter or Legal size, and many scanners produce odd sizes; printers and submission portals outside North America expect A4. This page opens the PDF page size converter with A4 pre-selected — upload, convert, download — and every page becomes exactly 210 × 297 mm with its content scaled to fit and centred. Mixed-size documents come out uniform.
The work is done in your browser with pdf-lib, so the file is never uploaded and text stays crisp. Use Fill instead of Fit if you prefer edge-to-edge pages over small margins.
How to change a PDF’s page size
- 1Drop your PDF into the upload box. The tool shows the page count and the current page size (for example "A4" or "Letter").
- 2Choose the new page size: Long bond paper (8.5 × 13), A4, Letter / Short, Legal, A3, A5 or a custom size in millimetres.
- 3Keep Orientation on Auto so landscape pages stay landscape, and keep Content scaling on Fit (nothing is cut off). Choose Fill only if you would rather crop edges than have margins.
- 4Click Convert. Each page is scaled and centred onto the new size in your browser.
- 5Download the PDF and print it at 100% / Actual size on the matching paper.
Frequently asked questions
How do I change a Letter PDF to A4?
Upload it here (A4 is pre-selected), click Convert and download. Letter is slightly wider and shorter than A4, so Fit shrinks the content by about 3% to keep everything on the page.
Does converting to A4 reduce quality?
No — pages are scaled as vectors, not re-rendered as images, so text and lines remain sharp and the file size stays about the same.
Can I use a custom size instead of A4?
Yes. In the tool choose "Custom size (mm)" and type any width and height.
Is my PDF uploaded?
No, the conversion runs entirely in your browser.
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