About PDF page size changer
Page size in a PDF is the media box: four numbers on each page object giving its rectangle in points, where 72 points make an inch. Changing size therefore is not a setting you flip — a new page of the target dimensions has to be created and the original page drawn onto it as a form XObject, wrapped in a transformation matrix. Scale-to-fit computes the smaller of the width and height ratios so the entire page fits without distortion, which is why converting A4 to Letter leaves thin bands rather than stretching the content. Centring instead applies no scale at all, preserving absolute measurements for drawings that must stay dimensionally true, at the cost of clipping if the target sheet is smaller. Because the source page is embedded rather than rasterised, text stays selectable and vectors stay sharp at the new size; only the coordinate transform differs.
How to PDF page size changer
- 01
Load the document
Drop in the PDF whose pages are the wrong size.
- 02
Pick the target size
Choose A4, Letter, A3, Legal, A5 or Tabloid, and decide whether orientation should follow each source page.
- 03
Choose scale or centre
Scale to fit keeps everything visible; centre at original size keeps measurements true but can clip.
- 04
Convert and download
Press the action button and save the resized document.
What this tool does
- Six standard sizes covering both ISO and North American conventions
- Scale-to-fit is proportional, so content is never stretched or squashed
- Centre mode preserves true dimensions for scale drawings
- Per-page orientation matching, so mixed documents are not forced one way
- Content is embedded as vector, not rasterised — text stays selectable
Limitations worth knowing
Every PDF tool has constraints. Stating them plainly is more useful than discovering them halfway through your work.
- Content does not reflow. Scaling shrinks or enlarges the whole page, so small print becomes smaller when converting down to A5.
- Scale-to-fit leaves uneven margins when aspect ratios differ, as with A4 to Letter.
- Centre mode clips content that falls outside a smaller target sheet.
- Interactive form fields and annotations may not follow the transform correctly; flatten the form first if fidelity matters.
How your file is handled
This tool runs entirely inside this browser tab. When you choose a file, your browser reads it from your own disk and hands the bytes to JavaScript running on this page — no network request carries your document anywhere. You can confirm that yourself: open your browser’s developer tools, switch to the Network panel, and run the tool. You will see no upload.
Nothing is stored after the fact. Closing or reloading this tab discards the file, the result and everything derived from them, because none of it ever left your machine. Read how local processing works.
Questions about PDF page size changer
Will my text be stretched when the aspect ratio changes?
No. Scale-to-fit uses a single proportional factor derived from the tighter of the two dimensions, so the content keeps its shape and the difference shows as margin instead of distortion.
When should I use centre instead of scale?
When absolute size matters — a scale drawing, a form with a measured field, or artwork that must print at exact dimensions. Centring keeps 100% size but will clip if the new sheet is smaller.
Does resizing make the pages blurry?
No. The original page is embedded as a vector form object and transformed, so text and line art scale cleanly. Embedded photographs keep their pixel data and only appear softer if enlarged substantially.
Why do my form fields shift or disappear?
Widget annotations carry their own coordinates and are not part of the page content being transformed. Flatten the form before resizing so the field appearances become ordinary page content.
Tools that pair with this one
- Convert PDF to A4Put your document onto standard A4 pages.
- Convert PDF to LetterPut your document onto US Letter pages.
- Resize PDF PagesScale your pages up or down without re-rendering the content.
- Crop PDFTrim away margins, scanner borders and dead white space.
- Flatten PDF FormBake the current answers into the page and drop the fillable layer.
- Convert PDF to LandscapeMake the document read wide, without disturbing pages already landscape.
Read more about this
- How to merge PDF filesJoining documents copies pages into a new PDF rather than re-rendering them. This guide covers the actual order controls and the document-level features that a merge cannot promise to preserve.5 min guide
- How to split a PDF into separate filesSplitting turns one document into many. This guide explains the three split methods, how to pick between them, and what each output does and does not inherit.5 min guide
- How to delete pages from a PDFDeleting pages rebuilds the document from the pages you kept. Lossless for the survivors, and not the size fix people expect it to be.4 min guide