How to crop a PDF and trim its margins
Updated
Contents
To crop a PDF, open Crop PDF, add your file, and set how much to trim under Crop margins: one value for all four sides, a separate value for each side, or Auto, which finds the white margins around each page's content for you. Then press Crop PDF and download the result.
You can measure in pt, mm, or in, crop every page or only the pages you list, and check the result in the Crop preview before anything is cropped. Crop PDF runs in your browser tab, so your PDF stays on your device; it opens one file at a time, up to 100 MB.
Cropping hides the edges rather than deleting them: the tool shrinks each page's visible area, and the content outside it stays in the file, out of view. Selectable text stays selectable, because nothing is redrawn.
Step by step
- 1Open the Crop PDF tool and drag your PDF into the drop area, or click it to choose the file. It stays on your device.
- 2In the Crop margins section, choose Uniform for one All sides slider, or Per side for separate Top, Right, Bottom and Left sliders, and pick pt, mm, or in as the unit. You can drag a slider or type a value in the box beside it.
- 3For automatic margins, choose Auto and press Find white margins. The tool says how many pages it found content on and names any blank page, which it leaves uncropped.
- 4In the Pages section, keep All pages, or choose Selected pages and type a list such as 2-4, 7.
- 5Check the Crop preview, then press Crop PDF and Download cropped PDF.
Set the margins yourself
Uniform trims the same amount from every edge with one All sides slider. Per side gives Top, Right, Bottom and Left their own sliders, so you can take a footer strip off the bottom and leave the other three edges alone. The unit buttons switch between pt, mm, or in; a value you type is read in the unit you chose.
Margins are measured on the page as your viewer shows it, so Top always trims the edge you see at the top, even on a page that is stored turned and only displayed upright. No page may end up narrower or shorter than 24 points: margins that would do that stop the run, and the message names the first page that failed.
Let Auto find the white margins
Auto renders each page in your browser at a low resolution, finds the area that holds anything darker than near-white, such as text, lines, images or a scanner's grey edge, and proposes margins that keep it with 6 points of white on every side. A page with nothing on it is named and left uncropped.
With content on more than one page you choose between Each page its own box and Same box on every page. Same box on every page uses, for each edge, the smallest margin any page needs, so no page loses content. In Auto, the Crop preview shows the page itself under the proposed box, with Previous page and Next page to check each one.
A scan with a grey or speckled background has no white to find, so Auto may crop little or nothing there. Set the margins yourself instead.
What cropping keeps
The page content itself is not changed: the crop box, the region a PDF viewer shows, gets smaller, and whatever sits outside it is still in the file. That makes cropping a poor way to hide private information; for that, use a redaction tool. It also means the file does not reliably get smaller, so use Compress PDF when size is the goal.
Margins are measured from the page's current visible area, so cropping an already-cropped file trims further. If a page is on its side, turn it upright with Rotate PDF first, so the edges you see are the edges you name.
Common questions
Can I crop each side of a PDF by a different amount?
Yes. Under Crop margins, switch from Uniform to Per side and four sliders appear: Top, Right, Bottom and Left. Setting only Bottom, for instance, removes a footer strip and leaves the other edges alone.
Can it remove white margins automatically?
Yes. Choose Auto and press Find white margins. Each page is checked for content, and the proposed crop keeps it with 6 points of white around it; a blank page is named and left uncropped. Check each page in the preview before you press Crop PDF.
Can I set the margins in millimetres or inches?
Yes. Pick pt, mm, or in beside the sliders. Each slider shows its value in that unit as you drag, and the box beside it takes a typed value in the same unit.
Does cropping delete the content outside the margins?
No. Cropping shrinks each page's visible area; the content outside it stays in the file, out of view. Nothing on the page is redrawn, so selectable text stays selectable.
Why is the Crop PDF button greyed out?
It stays off while every slider sits at 0, because there is nothing to crop, and in Auto until Find white margins has found content on at least one page. A Pages list that is empty, backwards or past the last page is rejected with a message.