Crop PDF Margins — Free & Private
Trim white borders off a PDF so the content fills the page. Drag a box on the page, or let Auto-trim cut each page to its content — on every page, one page, or a range, all in your browser.
In short: drop a PDF, drag the box on the page preview — or press Auto-trim to cut each page to its content — choose which pages it applies to, and download. It runs on your device and nothing is uploaded. Important: cropping a PDF hides the trimmed area rather than deleting it — it is not redaction, and the section below explains what to do instead.
- Does cropping delete the trimmed content?
- No. It changes the page’s visible area and leaves everything else in the file. Anyone can undo it in a PDF editor. This is how PDF cropping works everywhere, not a limitation here.
- So can I use it to hide confidential information?
- No — please do not. The text is still in the document and recoverable. Real redaction removes the content, and the section below says how to get it.
- What is it good for, then?
- Tidying: removing scanner borders, trimming wide margins so the text fills a tablet screen, cutting off a header or footer that is in your way.
- Is my PDF uploaded anywhere?
- No. The crop is applied in your browser, so the document never leaves your device.
- Can I crop pages differently from each other?
- Yes. Choose "This page only" and each page keeps its own box; Auto-trim gives every page a box fitted to its own content.
- Is it free, and is there a limit?
- Free, with no task, page or size limit. Sejda allows 3 tasks an hour on its free tier and Smallpdf 2 a day.
How to Crop a PDF
Drop it onto the tool, or click to browse. Nothing is uploaded.
Drag the box on the page, or press Auto-trim to cut each page to its content.
All pages, this page only, or a range.
Save the cropped PDF. The trimmed area is hidden, not deleted.
Features
Drag to crop
A box with eight handles on the page itself, cut shown in mm.
Auto-trim
Each page cut to its own content automatically.
Any pages
All pages, one page, or a range such as 2-5.
Rotated pages
Measured as displayed, so the top is the top.
Protected PDFs
Restricted and password files open.
Nothing uploaded
It all runs in your browser.
Cropping hides content — it does not remove it
This is the most important thing on the page, so it is near the top: cropping a PDF does not delete anything.
A PDF page carries two rectangles. The MediaBox is the physical page. The CropBox is the part a reader displays. Cropping sets a smaller CropBox and leaves everything else alone — the text, images and annotations in the trimmed strip are still in the file, exactly as they were, simply outside the window.
Demonstrated rather than asserted: trim 20% off a 400×400 page here and the result has a CropBox of 400×320 and a MediaBox still reading 400×400. Reset the CropBox in any PDF editor — a one-line change — and the hidden strip is back, with its text selectable and searchable. Some readers will even find it in a text search without being asked to.
This is not a shortcoming of this tool. It is what cropping means in the PDF format, and every cropping tool behaves this way, whether or not it tells you. What is a shortcoming is not saying so, because the obvious use for "cut the top off this page" is hiding a letterhead, a name, a figure or a signature — and someone doing that here would be publishing the very thing they meant to remove.
What to do instead
- If the content must be gone, use a tool with a real redaction feature (Acrobat’s Redact, or a command-line tool that rewrites the content stream) and then check the result — open it, select all, copy, and paste somewhere to see what comes out. Nearly every redaction failure that has made the news was a black rectangle drawn over live text.
- If the content can be flattened, convert the pages to images and rebuild a PDF from them: PDF to JPG, crop the images with Crop Image, then Image to PDF. The trimmed area genuinely does not exist in the result. The cost is that the text stops being text — no selecting, no searching, and a bigger file.
- If you only want it out of the way, which is the usual case, cropping here is exactly right and nothing above applies.
What cropping is genuinely good for
With the warning out of the way: cropping is genuinely useful, and the cases are all about making a document comfortable to read rather than about hiding anything.
- Scanner borders. A flatbed scan of a book or a page smaller than the glass comes with black or grey edges. Trimming them makes the document look deliberate and stops the borders dominating a thumbnail.
- Reading on a tablet or e-reader. An academic paper laid out for A4 has margins that waste a third of a small screen. Cropping them lets the reader zoom the text to fill the display — the single biggest improvement you can make to reading a PDF on a device.
- A header or footer in the way. A running header repeated on two hundred pages, or a footer with a draft watermark, can be cropped out for a reading copy.
- Slides with wide letterboxing. Exported presentations often sit in the middle of a larger page.
One thing cropping will not do is make the file smaller, and the reason is the same as the warning above: the hidden content is still stored. If size is the goal, Compress PDF is the tool.
Capabilities at a glance
What this tool does and does not do, stated plainly. The “No” rows are the point, not an omission.
| Capability | Supported | Detail |
|---|---|---|
| What it does | ||
| Crop by dragging a box on the page | Yes | Eight handles, drag to move, arrow keys to nudge; the cut is shown in mm. |
| Pages stay fully editable and selectable | Yes | Nothing is re-rendered; the text is still text. |
| Deletes the trimmed content | No | It is hidden, not removed — see below. This is how PDF cropping works everywhere. |
| Redaction | No | Not what this is. Use a tool that removes content, then check the result. |
| All pages, one page, or a range | Yes | The same box on every page, or a different box per page. |
| Auto-trim white margins | Yes | Each page is rendered and cut to its own content, with a small border kept. |
| Rotated and mixed-size pages | Yes | The box is measured on the page as displayed, so "top" is the top a reader sees. |
| Input | ||
| Any PDF | Yes | Including scans. |
| An encrypted PDF | Yes | A permissions-only file opens automatically; an open password is asked for and stays on your device. |
| Page or size limit | No | There is no server to protect. Sejda caps the free tier at 50 pages and 50 MB. |
| Task limit | No | Smallpdf allows 2 free tasks a day, Sejda 3 an hour. |
| Output | ||
| A normal PDF with smaller pages | Yes | Opens and prints anywhere. |
| A smaller file | No | The hidden content is still stored, so the size barely changes. |
| The original left untouched | Yes | The result is a new download. |
| Watermark | No | Nothing is added to the pages. |
| How it runs | ||
| Nothing is uploaded | Yes | The document never leaves your device. |
| Signup | No | There is no account. |
| Offline use | No | The page and pdf-lib load from the network first. |
Drawing the box, Auto-trim, and which pages
The box is drawn on the page as you see it. Drag its edges or corners, drag the middle to move it, or use the arrow keys (Shift+arrow pulls an edge in). The line under the preview says how much each side loses, in millimetres, so a 10 mm trim is a 10 mm trim.
Apply to decides where the box goes: every page, only the page you are looking at, or a range such as 2-5. A scanned book with mirrored gutters is two passes — odd pages, then even — or one Auto-trim.
Auto-trim renders each page and finds where the ink actually is, then fits a box around it with a small border. Every page gets its own box, so a short last page is not cut to the size of a full one. Afterwards, edits apply to one page at a time, so fixing one page does not undo the others.
Measuring the displayed page matters more than it sounds. A scan stored sideways with a “turn 90°” flag has its top on the left of the stored page; the previous version of this tool cut the stored top, which on such a page is a side. It now maps the box back through the rotation, and the download keeps your file’s name with _cropped added.