Add margins to a PDF
Add white space around every page for binding, hole punching or handwritten notes. Lossless mode keeps links, bookmarks and form fields intact.
- Runs in your browser
- Files are never uploaded
- Free, no account
Your PDF never leaves this tab — here is how to check
This page has no upload step and no server behind it. Two ways to confirm that yourself, neither of which requires trusting us:
- Turn off Wi-Fi or put the device in aeroplane mode after this page has loaded, then run the tool. It still works.
- Open your browser’s developer tools, switch to the Network tab, clear it, and process a file. No request appears.
The reason this matters: in 2025 the PDF service pdf.net was found exposing roughly 3.5 million user-uploaded documents, and formatter sites JSONFormatter.org and CodeBeautify leaked over 80,000 saved snippets containing live cloud credentials. Those are architectural failures — a file that is never sent cannot be exposed that way.
Two different ways to add a margin
“Add a margin” is ambiguous, and the two possible meanings produce very different files. This tool asks you which one you want rather than guessing.
| Grow the sheet | Keep the paper size | |
|---|---|---|
| What changes | The page rectangle gets bigger | The content gets smaller |
| Content scale | 100% — nothing moves | Shrunk to fit inside the margins |
| Final paper size | Bigger than the original | Identical to the original |
| Links, bookmarks, form fields | Preserved | Not carried over |
| Best for | Adding note space before printing large | Keeping a strict A4 requirement |
Grow-the-sheet is genuinely lossless: the only thing written into the file is a larger rectangle. Every drawing instruction, annotation and field stays exactly where it was, which is why it is the default.
How much margin do you actually need?
| Purpose | Suggested margin | Where |
|---|---|---|
| Two-hole punch (EU) | 20 mm | Left edge |
| Three-ring binder (US) | 25 mm / 1 in | Left edge |
| Comb or spiral binding | 25–30 mm | Left edge |
| Perfect-bound book, per side | 15 mm + 5 mm creep | Inside edge |
| Space for handwritten notes | 50–60 mm | Right edge |
| Safe printable area | 5 mm | All four edges |
Mirror margins for double-sided printing
In a bound document the binding edge is on the left of a right-hand page and on the right of a left-hand page. A fixed 25 mm left margin therefore buries the text of every even page in the spine while leaving a useless gap on the outer edge.
Switch off “same margin on all four sides” and the mirror option appears. With it on, the left and right values are swapped on even-numbered pages, so the wide margin always falls on the inside. Set left to the binding margin, right to the outer margin, and the whole document imposes correctly.
Why the resulting page is not A4 any more
This surprises people, so it is worth saying outright: in grow-the-sheet mode, an A4 page with a 20 mm margin added on every side becomes 250 × 337 mm. That is intentional — it is what “keep the content at full size and add space around it” means geometrically.
When you print it, choose fit to page and the printer will bring it back down onto A4, giving you the margin you asked for with the content 84% of its original size. If you would rather the file itself stay A4, turn grow-the-sheet off and the shrinking happens here instead, where you can see the result before you print.
Everything happens in this tab
Adding a margin to a signed contract, a thesis draft or a medical report should not require handing the document to a stranger’s server first. pdf-lib rewrites the page rectangles here, on your machine. There is no upload endpoint in this product at all.
Questions
Why is “grow the sheet” lossless but the other mode is not?
Growing the sheet only enlarges the page rectangle recorded in the file — no object inside the page moves, so annotations, links, bookmarks and form fields are untouched. Keeping the paper size instead means the content must be shrunk and re-drawn onto a fresh page, which rebuilds the page object.
What are mirror margins for?
When a document is printed double-sided and bound, the binding edge alternates between left and right. Mirror margins swap the left and right values on even-numbered pages so the wide margin always lands on the inside edge of the spread.
How much margin does a three-hole punch need?
Around 25 mm (1 inch) on the binding edge is the safe figure for a standard three-ring binder or a comb binding; 20 mm is enough for a simple staple or a two-hole punch.
Will the printed page be bigger than A4 now?
In grow-the-sheet mode, yes — an A4 page with 20 mm added all round becomes 250 × 337 mm. Print it with “fit to page” to bring it back onto A4, or use the keep-the-paper-size mode so the sheet never changes.