How to change PDF page size

How to change the page size of a PDF, step by step

Changing the page size of a PDF takes under a minute, in three steps:

1. Open the Page size tool.
2. Choose the file: drag the PDF into the tool window, or click to pick it.
3. Pick the format, A4, A3, A5, Letter or Legal, and apply. You get the PDF with the new format on every page.

Nothing to install, no account and no upload wait. The chosen format applies to every page of the document at once, and the processing runs in your browser, start to finish.

A4 vs Letter: what happens to the content

Changing the page size does not rescale what is written on it, and that is the most important thing to know about this tool. Only the sheet size changes, what the PDF format calls the MediaBox, and the content stays exactly where it was, measured from the same corner. An A4 document set to Letter, which is narrower and shorter, ends up with its right and bottom margins outside the visible area; set to A3, which is bigger, it ends up with a blank strip of paper around it. Text stays text, images stay where they were and forms keep working: nothing inside the page is touched.

That is why the tool is for two concrete cases. One: switching the print format of a document meant for a different sheet, knowing the margins may need reviewing afterwards. Two, the more common one: unifying a PDF with pages of different sizes, the result of merging several files, for example, so all of them end up with the same format, even though the content of each one stays in its original spot.

Tips for changing the page size

• Before shrinking the format, check that the content fits. The content is not rescaled: an A4 document set to Letter ends up with its right and bottom margins outside the visible area. If the text sits close to the margins, it is worth checking beforehand whether it fits the target format.
• Use it to unify formats. If the PDF came from several files merged together and has pages of different sizes, this tool gives every page the same format in one go. To put the pages in the order you want before unifying, use Reorder pages; to trim the white margins left around the content, Crop margins.
• Text, images and form fields stay intact. Nothing inside the page is touched: only the sheet changes. You can safely use it on documents with form fields, they keep working in the new file.
• Nothing is sent to a server. The processing runs in your browser, start to finish, and no PDF leaves your computer.
• The file weight does not change in any meaningful way. Nothing is added or removed, only a geometric value per page is changed. If the goal is a lighter file, the right tool is the compressor. To see what is really inside the file before touching it, use PDF properties.

Is changing the page size free? What are the limits?

No. This tool is part of the Premium subscription, EUR 1.99 a month, which removes the limits on every tool and adds OCR. Sign PDF opens on the free plan, with one signature a day.

Sources

• BestPDFInTheWorld, Tamanho de página
• MDN, File API
• pdf-lib