How to split and merge PDF: Tools and steps

Key points of this article

Splitting and merging are often done in succession: split the required pages first, and then merge them with other files. It is easier to complete them in the same editor than to switch tools back and forth.
Before merging, uniformly check the number of pages, page orientation and whether each document is a scanned copy, which can reduce subsequent rework.
Write down the page number range you want to keep before splitting, and check the first and last pages before exporting to avoid missing pages or multiple pages.
After merging, read through it from the beginning to check the page order, direction and content integrity. If there is any misalignment, use the rearrange or delete function to adjust and then export.

Many people have a PDF in hand and only need a few pages; or they need to put together several reports, contracts, and scans in order. These two things seem to be two operations, but in fact they are often connected together: first remove the required pages from the long file, and then merge them with other files. If it can be done in one tool, there is no need to export and reopen it repeatedly, and there will be few format changes in the middle.

This article is written for readers who need to organize documents, submit materials, and archive materials. The following will first talk about how to choose the method in different situations, then give the steps to split and merge in the PDF editor of the OmniDoc desktop client, and finally the verification method after exporting. After reading it, you will be able to judge for yourself how to disassemble and combine it, and know where the results need to be read again.

How to split and merge PDF? One sentence conclusion

The conclusion is simple: when the number of files is small and you only need to split a few pages or put together a few copies, do it directly in a PDF editor; when there are many files and require a unified format, make the verification process more detailed. The table below gives suggestions based on common situations.

your situation	Recommended practices	reason
Just a few pages in a long document	Select the page number range in the editor to split and export as a new file	The content of the page remains the same and does not need to be reformatted.
You need to combine two or three PDFs into one in order	Use the merge function to confirm the order one by one after importing.	You can clearly see the page number and location of each copy before merging.
The separated pages should be combined with other documents	Split first, then merge, all done in the same editor	One less intermediate export and less file clutter
The document is a scanned copy and the text needs to be copied	First use OCR to recognize text, then split or merge	After recognition, you can select the text to facilitate checking the content.
Just want to adjust the page order or delete a few pages	Use page operations directly: delete, rotate, rearrange	No need to split into multiple files, modification is more intuitive

Before you start: Confirm these points first

Determine the page number range first. Before splitting, write down the pages you want to keep, such as "Pages 3 to 8" or "Pages 1, 5, 12." When the original document has many pages, it is easy to miss the cover, attachments or signature page when operating from memory, so it is safer to write clearly first.
Confirm that each file can be opened normally. If you can turn to the last page after opening, it means the file is basically complete. After the damaged files are merged, the problem will remain with you, and it will become more difficult to find out later. It is recommended to eliminate it before starting.
Unify the page direction. When the horizontal and vertical versions are mixed together, the combined reading will be awkward. If individual pages are in the wrong orientation, it is easier to rotate them first and then merge them than to go back and modify them after exporting.
Determine whether it is a scanned copy. Try using the mouse to select a piece of text: the text version that can be selected is usually the text version; the full page image that can only be selected is mostly a scanned copy. Scanned documents can also be split and merged, but if you need to copy text or search for keywords, you should first perform OCR recognition and check the recognition results.
Keep the original backup. Split and merge are generally exported as new files, do not overwrite the originals. In this way, if the page number is miscalculated, you can go back to the original and process it again.

Steps to split and merge PDFs in OmniDoc desktop client

The web version of omnidoc.top mainly provides document translation. Splitting and merging should be completed in the desktop client. The following steps use the PDF editor as an example.

Download and install the desktop client. Open download.omnidoc.top and choose the Windows, macOS or Linux version to install according to the system you are using.
Open the PDF editor and import the original file. Select the PDF you want to split and wait for the file to load completely.
View page thumbnails. Browse page by page, confirm the total number of pages and page order, and compare it with the page number range written previously.
Split out the required pages. Select the page number range you want to keep, perform splitting, and get a new file containing only these pages.
Import other PDFs you want to merge. Add the files that need to be spliced into the editor and arrange them in the order of contracts, reports or chapters.
Execute merge and adjust page order. After completing the merge, if you find that the positions of some pages are wrong, use the rearrange function to adjust the page positions; use the delete function to remove the extra pages.
Process the scanned document (if necessary). If the document is a scan and requires text content, use the OCR function to identify it first, and then perform subsequent operations.
Save as new PDF file. The file name should indicate the content and scope as much as possible, such as "Contract_Pages 3 to 8_Consolidated Version", and store it separately from the original.

Check each item after completion

After getting the results, do not send or file them directly. Please read them one by one according to the table below.

Check items	How to see	What to do if there is a problem
Number of pages	Check whether the first and last pages are correct compared with the planned page number range.	When there are many or few pages, return to the original to redefine the scope before splitting
Page order	From beginning to end, focus on the chapter transitions	Use the rearrangement function to adjust and then save again
Page direction	Check whether horizontal and vertical layouts are chaotic	Rotate the corresponding page and save again
The content is complete	Check whether the header, attachments, and signature pages are all present	Restore the corresponding original pages and merge them again
Text availability	Try selecting the text and searching for keywords in the scan	If there is no text, OCR is performed first, and the recognition results are checked against the original
Files can be opened	Try switching to another device or reader to open it and see if it displays properly	Re-export and confirm that the original backup is still intact

🎯 Which method suits you?

Only split a few pages of a long document: Focus on checking the page range and the first and last pages; after splitting, you can save without merging.
Combine multiple materials into one: Focus on the import order and page orientation, merge them, and scroll through chapter by chapter at the transitions.
Documents contain scans: First OCR, then split or merge, and compare the identified key content with the originals one by one.

❓ Frequently Asked Questions (FAQ)

1. Will the split files become smaller?

Not necessarily. File size depends on the number of images and fonts on the page. Splitting only a few pages usually shrinks the size, but if many images are kept on the page, it's normal for the shrinking to be less noticeable.

2. Can the original bookmarks and table of contents still be used after merging?

After merging or splitting, bookmarks and directory page numbers in the original file may not match the new file. After exporting, please refer to the actual page and re-check the table of contents and the beginning page of the chapter.

3. How to merge two PDFs in the PDF editor?

Import two files in the PDF editor one by one, confirm the order, perform merging, then check the connection from the head, and finally save as a new file.

4. Free splitting and merging PDF files—what should you look for when choosing a tool?

When choosing a free tool, it's recommended to check three points first: whether there are restrictions on file size and page count, whether the exported file has a watermark, and whether the file will be uploaded to the internet. It also depends on whether the layout is retained after splitting and merging. These factors determine whether the result is usable even more than the word "free."

5. Is it okay to just want to split and merge using online tools?

Yes, online conversion websites generally offer split and merge functions. However, for sensitive documents such as contracts or medical records, first confirm the security of uploads; if it can be completed locally, prioritize local processing.

📝 Summary

Splitting and merging PDFs is not complicated; the key is to first determine the page number range and unify the document status, then proceed sequentially and verify item by item. Splitting and merging in the same editor reduces the number of intermediate files and makes it easier to control the final result. Review it multiple times before exporting to save time compared to reworking afterward.

Open OmniDoc and use the PDF editor to process your files