PDF Auto Split by Size/Count
Automatically split PDF into smaller parts by file size or page count.
Drag & drop files here, or click to select
Split Options
How to Auto Split PDF by Size or Page Count
Upload the PDF document from your device.
Select the splitting mode (by target file size limits or exact page numbers count).
Input the limit values (e.g. 5 MB or 3 pages).
Click the Auto Split button to divide and download your parts.
Why Use SonuPDF to Split PDFs?
Fast Client-side Splitting
Split operations are processed locally in your web browser. In contrast to other services, no document pages are sent to a cloud server.
Multi-mode Options
Split documents dynamically by setting maximum file size thresholds per part or splitting at regular page intervals.
Automatic File Packing
Output files are generated instantly. You can choose to download parts separately or packed in a zip file.
Resource Protection
Handles large documents efficiently inside the local sandbox without browser memory leaks.
Frequently Asked Questions
The tool parses the PDF file structure locally and writes the page streams into separate output file objects entirely in your browser memory.
This is useful when you need to send files via email attachments or upload to portals that have strict file size limit restrictions.
No. The underlying text vectors, image streams, and metadata structures are preserved exactly as they are without re-compression.
You must unlock the PDF file first or supply the correct open password before splitting the pages.