How to trim and crop a PDF

▶ 1. Trimming and cropping are two different things

Confusing the two terms wastes time, because they lead to different tools.

• ✓ Trimming acts on the document: splitting it into several files, extracting part of it or deleting pages you do not need.
• ✓ Cropping acts on the individual page: reducing white margins, removing the black edges of a scan, adjusting the visible area.

The starting point is often identical — “this PDF is not right as it is” — but the solution differs. With 123 PDF Editor PRO both operations happen in the browser, without installing desktop software and without uploading the document online.

⧈ 2. Trimming: splitting the document

This is what you need when a single file is too long or too heavy, or when you have to hand over only part of it.

1. Install the extension from the download page and open the file with Choose a PDF.
2. Go into Organize pages.
3. To get several files at regular intervals, set Split every N pages and click Split PDF.
4. To extract a specific part, select the pages you need and use Extract selected pages.
5. The topic is covered in depth in the guide on how to merge and split PDFs.

✕ 3. Trimming: deleting the pages too many

Blank pages produced by the scanner, irrelevant attachments, duplicates: removing them makes the document more readable and much lighter.

1. In Organize pages scroll through the thumbnails and find what you do not need.
2. Delete the superfluous pages from the grid.
3. Reorder the rest by dragging the thumbnails, if deleting has left an illogical sequence.
4. Confirm with Apply page changes.

▣ 4. Cropping the margins of the pages

This is the operation you need when the content is right but lost in enormous white space, as is typical of scans.

1. Still in Organize pages, open Crop page.
2. Set the margins to remove in millimetres, side by side.
3. Proceed cautiously: an over-aggressive crop cuts into the text, and recovering it means starting again from the original document.
4. Apply and check the result on one page before extending it to the whole document.

▤ 5. Making the page format uniform

When a document comes from different sources, the pages can have different sizes: in print the result looks untidy.

1. Use Resize page to bring every page to the same format: A4, Letter, Legal or a custom size.
2. Correct the orientation as well with Rotate left or Rotate right where needed.
3. Making the format uniform before printing stops some pages coming out shrunk or with clipped edges.

⇲ 6. Trimming to make the file lighter

If the reason you want to trim is the weight of the document, it is worth knowing which lever works best.

Deleting pages reduces the file far more than compression does, especially when those pages contain scans or high-resolution images. So the order to follow is: first take out the useless pages, then compress what is left.

1. Remove the pages you do not need as described above.
2. Compress the resulting document following the guide on how to compress a PDF.
3. If you only need part of the document, extraction is better still: you get a file containing exclusively what interests you.

? 7. Frequently asked questions

The questions that come up most often on this topic.