I just added a Crop PDF tool to MyPDFLabs, my free set of online PDF tools. It’s for the moment when a PDF has too much empty space, like a shipping label in the corner of a full page, or a scan with wide margins. I wanted to share what it does and what I focused on.

What it does

The tool has a live preview of your page on the left and the controls on the right.

Four quick presets: Trim Margins (8%), Shipping Label, Cut Headers/Footers and No Margin (0%)
Four sliders: Top, Bottom, Left and Right Margin Trim, each set as a percentage, so you can cut more from one side than another
Live preview: a dashed outline marked “Cropped Output” shows what will stay, and the shaded area around it shows what will be removed
Page navigation: Prev and Next buttons let you check the crop on other pages before you download
Apply scope: All Pages or Only Page 1
Reset to go back to the defaults, and Choose Different PDF to start over with another file
No sign-up and no watermark on the core tools
Files up to 500MB, with uploaded files deleted automatically after processing
What I thought about while building it

Cropping looks simple, but a few details decide whether the tool is pleasant to use:

Show the result before the download. Numbers on a slider are hard to judge, so the preview marks exactly what will be cut. That saves a lot of trial and error.
Presets for the common cases. Most people want one of a few things: trim the margins, remove a header and footer, or cut a shipping label out of a full page. A preset gets them close in one click, and the sliders handle the rest.
Percentages instead of fixed units. A percentage setting makes it easier to use the same crop on pages of different sizes.
Let people check more than one page. A crop that looks right on page 1 can cut text on page 3, so the Prev and Next buttons are part of the main layout.
Separate scope for mixed documents. Sometimes only the first page needs cropping, such as a cover or a label, so Only Page 1 sits next to All Pages.
What I’d like feedback on
Are the four presets the right ones, or is a common case missing?
Is anything confusing about the sliders or the preview?
Would you like to crop different pages by different amounts?
Which PDF tool should I add or improve next?
Try it

You can try it here: mypdflabs.com/tools/crop

Thanks for reading, and I’ll reply to every comment.