How to merge multiple PDF selected pages into one file

Key points of this article

First merge the required PDFs into one file, then delete extra pages and adjust the order. The page numbers are always in the same place, making it less likely to miss pages than copying them separately.
Write down the page numbers required for each document in the preview before starting. After merging, compare the records page by page for faster positioning.
The encrypted PDF must be able to be opened normally; if you want to select or search for text in the scanned document, you must first perform OCR and check the recognition results.
All operations are performed on new files. After exporting, the page number, order and content are checked page by page, and the original file is kept as a backup.

Many people have several PDFs in their hands: attachment pages of contracts, chart pages in papers, and several slides in conference materials. What is really needed is often just a few pages, and finally they need to be combined into a file to send to others or archive. If you merge the entire document as it is, the result will be thick and messy, and you will have to rummage through it for a long time.

This article is for those who need to select pages from multiple PDFs and merge them into a new document. The method can be broken down into three things: first merge, then delete pages, and finally sort. The following steps are completed in the PDF editor of the OmniDoc desktop client.

After reading this article, you will be able to judge which situations require processing files first and then merging them, know how to do each step specifically, and know where to check after exporting.

How to merge selected pages from multiple PDFs? One sentence conclusion

First merge all source files into one file, then delete unnecessary pages in the merged result, adjust the order, and finally export. The page numbers are always in the same file, making it less error-prone than copying pages one at a time.

your situation	Recommended practices	reason
Only a few pages per document	Delete redundant pages after merging all files	All pages are in one place, and the page numbers are directly visible, making it difficult to miss a selection.
There are many files or a single file is very large	First delete obviously unnecessary pages in each file and then merge them	The merged file is smaller and the scope of page-by-page inspection is smaller.
The source file is a scanned copy	After merging page selections, do OCR and then check the text.	Scanned documents are essentially pictures. To search or select text, you must first identify it.
A password is set to open the file	First open it normally with the password and confirm that it can be read.	Files that cannot be opened cannot participate in the merge
Page order must be consistent with the original	After merging, rearrange according to original page number	The order of merging depends on the order of files and requires manual verification.

Before you start: Confirm these points first

Page Number: Use Preview to flip through the documents one by one and write down the required page numbers, such as pages 3 to 5 of the contract and page 12 of the attachment. The page numbers will change after merging, so you can quickly match them if you have records.
Can the file be opened normally: The encrypted PDF must be open before it can be processed. If you can't open it, first make sure you have permission to use the file, and then find the correct password.
Text or scan: Try selecting a text in the PDF. If you can't select it, it's probably a scanned copy. Scanned documents can also be merged into page selections, but if you want to copy or search text, you need to do OCR first. The recognition results may be wrong, and key numbers and names must be checked against the original.
File order: The merge order determines the order of pages. Arrange the source files according to their purpose first, so that you can make less adjustments when merging them.
Keep originals: All operations are performed on the new merged files, and the original files should not be deleted or overwritten.

Steps to merge multiple PDFs and select pages in OmniDoc

Open the OmniDoc desktop client (download address: download.omnidoc.top) and enter the PDF editor.
Open the first PDF and confirm whether its page count and content are consistent with what you recorded.
Use the merge function to add the remaining required PDFs in order to generate a merged file.
Go through the merged results page by page, mark the unnecessary pages, and write down the page numbers.
Use the Delete Page function to remove these pages. When there are many page numbers, write them all down first, and then delete them all at once to avoid deleting and misaligning them at the same time.
If the order of the pages is wrong, use the adjust order function to move the pages to the target location.
If the orientation of some pages is wrong, use the rotation function to correct it.
After confirming that it is correct, save or export it as a new PDF file. The file name will indicate the content and date for easy search in the future.

Check each item after completion

Check items	How to see	What to do if there is a problem
Number of pages	Add the number of pages selected in each file and compare it with the total number of pages in the result	The number of pages does not match. Go back to the merge results to check whether they were deleted by mistake.
order	Read page by page and compare it with the original page number or title	Correct using the adjustment sequence function
Complete content	Check whether tables, pictures, and formulas are displayed normally	In case of an exception, return to the source file to confirm whether the problem is with the original file itself.
direction and edge	Check whether the page is correct horizontally and vertically, and whether the text on the edges is cut off.	Use the rotation function to correct; for edge abnormalities, return to the source file for verification.
text availability	Try selecting text and searching for keywords	The scanned document is first subjected to OCR, and then the important content is randomly checked against the original document.
Original backup	Make sure the original file is still saved	If it has been lost, do not rush to delete the new file, check again first

❓ Frequently Asked Questions (FAQ)

1. Merge first and then delete pages, or delete pages first and then merge?

In most cases, it is recommended to merge pages first and then delete them, because the page numbers are unified and errors are less likely to occur. If the source files are large, you can first delete obviously unnecessary pages in each file and then merge them, so that the intermediate file will be smaller.

2. The page sizes of different files are different. What will happen after merging?

Page sizes may be inconsistent after merging. If there is only a slight difference, it does not affect reading. If the difference obviously affects the use, it is recommended to return to the original document for confirmation before deciding whether to reprocess it and merge it.

3. A password is set for PDF, what should I do?

First make sure you have permission to use the file and can open it normally with the correct password. Files that cannot be opened cannot participate in the merge, and the opening problem needs to be solved first.

4. Can the scanned PDF be searched after being merged?

The page that was originally a picture is still not directly searchable after merging it. Only after OCR recognition can you search and select text. The recognition results may be wrong, and important content should be checked against the original.

5. Is it safe to merge files using online tools?

Before choosing an online tool, you can look at several things: file size and page limits, whether the output file has a watermark, how to write a privacy policy, and whether to retain the original layout after merging. Documents involving sensitive content such as contracts and medical records will be given priority to be processed locally.

📝 Summary

To merge selected pages from multiple PDFs, the key is to merge them first, then delete pages, and then sort them. Note down the page numbers before starting, confirm that the file can be opened normally, and check page by page after exporting. Keep the originals as backups, and the results will be guaranteed.

Open OmniDoc and use the PDF editor to work with your document