How this works in your browser
A PDF page carries two rectangles: the MediaBox, which is the full physical page, and the CropBox, which is the region a viewer actually displays. Cropping here uses pdf-lib to set a new CropBox inset by the margins you specify, leaving the MediaBox and all the page content untouched. That is why the operation is instant and lossless, and equally why it is not a way to remove anything: the content beyond the CropBox is still present in the file, merely outside the window the reader draws. Making the trim permanent requires rendering the page as it now appears, which is exactly what the Flatten tool does.
Crop PDF vs. traditional online converters
| Feature | Crop PDF (in-browser) | Traditional online converters |
|---|---|---|
| File upload required | No - never leaves your device | Yes - file is sent to a server |
| Processing queue | None - starts instantly | Often, especially at peak times |
| Watermark on output | Never | Common on free plans |
| Usage limits | None - free, unlimited use | Often capped per day or file size |
| Works offline once loaded | Yes, for most tools | No - requires a live connection |
| Account required | No | Often, for anything beyond a trial |
How to use Crop PDF
- 1
Open the Crop PDF tool
Go to tools.slaytic.com and open the Crop PDF tool. No sign-up or account required.
- 2
Set your margins
Enter how much to trim from the top, bottom, left and right in millimetres, setting each edge independently.
- 3
Preview and save
Check the preview to confirm nothing important is cut off, then save the cropped document.
Common ways to use Crop PDF
Trimming scanner whitespace
Remove the wide empty borders a flatbed scanner adds around a smaller original.
Removing printer marks
Cut crop marks, colour bars and bleed edges off a print-ready PDF to get a clean reading copy.
Fitting a different page size
Trim pages to suit a specific print format or to reduce wasted margin when reading on a tablet.
Frequently asked questions
Does cropping permanently delete content outside the crop area?
In PDFs, cropping sets a CropBox that hides content outside the margins - the underlying content is still in the file. Flatten the PDF afterwards if you need to permanently discard the hidden area.
Can I set different crop amounts for each edge?
Yes. Top, bottom, left, and right margins are set independently, so you can remove a large header while keeping normal side margins, for example.
Can I crop individual pages differently?
The current tool applies the same crop to all pages. For page-by-page control, use the Organize PDF tool which allows individual page rotation and trimming.
Can someone recover what I cropped off?
Yes, and this is the single most important thing to know about PDF cropping. Cropping hides content by narrowing the visible window; it does not delete anything. The material outside the crop is still in the file and can be revealed by resetting the crop or extracted by text tools. Never rely on cropping to hide sensitive information. Use Redact PDF for that, which genuinely destroys the content.
How do I make a crop permanent?
Run the cropped file through the Flatten tool afterwards. Flattening renders each page as it currently appears, so the hidden area is discarded rather than carried along. Expect the trade-off that flattening also converts text to an image.
Does cropping reduce the file size?
Barely, for the same reason. The cropped-away content is still stored in the document, so you are changing what is displayed rather than what is kept. Flatten or compress afterwards if size is the goal.
Is my document uploaded anywhere?
No. The crop is applied inside your browser tab and the file is saved locally.