How to use it
- Choose the PDF. Its page count appears under the file name.
- Choose the Paper size: A4, US Letter or a custom size in millimetres. Then choose the Orientation, portrait or landscape.
- Click Resize pages and download the new file. Open it once to check the pages, because links and comments are not carried over.
How a page is fitted
Each page is drawn on the new paper at the largest size that fits without being cut off. Its proportions stay the same, and the white space left over is shared equally above and below, or at the sides. A page smaller than the paper is enlarged to fit it.
A page is drawn as you see it: a page that is turned stays turned, and the text and drawings on it keep their shape. The sizes are in PDF points, where one point is one 72nd of an inch.
- A4: 210 by 297 mm, which is 595.28 by 841.89 points. DIN, the German standards body, says A4 is defined in the international standard DIN EN ISO 216.
- US Letter: 8.5 by 11 inches, which is 612 by 792 points. This is the standard sheet size of the US federal printing rules.
- Custom size: any width and height from 20 to 1,000 mm.
What the new file does not keep
Each page is rebuilt as a drawing on the new paper. The links, comments and form fields that sat on the page are not carried over, and neither are the bookmarks or the title and author of the file. The new file is labelled as made by FireToolLand.
Example: a US Letter page on A4
A US Letter page is 612 by 792 points. On A4, which is 595.28 by 841.89 points, it is scaled by 97.3 % to 595.28 by 770.36 points. It is centred, with about 36 points of white above and below it.
The width of the page decides the scale, so the page touches both sides of the A4 sheet.
Frequently asked questions
Are my PDF files uploaded anywhere?
No. Your browser reads the file, draws each page on the new paper and makes the new file on your own device. Nothing is sent to our server.
Will the text stay selectable after resizing?
Yes. The text and drawings of each page are carried over as they were and drawn at the new size, so the text is still text that you can select and search.
Why do my links and comments disappear?
Each page is rebuilt as a drawing on the new paper, and the links, comments and form fields that sat on it are not carried over. Keep the original file if you still need them.
What is the difference between A4 and US Letter?
A4 is 210 by 297 mm. US Letter is 8.5 by 11 inches, which is 612 by 792 points; it is a little wider and a little shorter than A4.
Does the tool make the pages bigger or smaller?
It scales each page so that it fits the new paper and keeps its proportions. A page that is larger than the paper is made smaller, and a page that is smaller is enlarged to fill more of the sheet.
Sources
- DIN, the German standards body: the A4 press release, which says A4 is defined in DIN EN ISO 216
- GOV.UK Notify letter specification: A4 portrait is 210 x 297 mm
- US Government Publishing Office: Joint Committee on Printing regulations, the standard sheet of 8½ by 11 inches
- Adobe developer documentation: one unit in the default user space of a PDF is 1/72 of an inch
- pdf-lib, the open-source library that draws the pages on the new paper in your browser
Figures and text last checked on Thursday, November 12, 2026.