Split PDF by Size
Split Large PDF Documents by Maximum File Size (MB)
Drag and Drop PDF files here
Fast, 100% private in-browser processing. Your files never leave your device.
Automatically divide oversized PDF files into smaller chunks that comply with email attachment limits (e.g. 10MB or 25MB) or portal upload constraints without losing document quality.
How to use Split PDF by Size
Upload PDF
Select the large PDF file you need to partition.
Set Max Size
Specify the target maximum size per chunk (e.g., 5 MB, 10 MB, or 25 MB).
Generate Parts
Click 'Split by Size' to automatically calculate page boundaries and download the split parts.
Key Features & Capabilities
Intelligent Size Boundary Calculation
OM PDF dynamically inspects page byte sizes to create balanced parts that fit under your specified size threshold.
Ideal for Email Attachments
Easily comply with Gmail (25MB), Outlook (20MB), and corporate firewall attachment limits.
Zero Cloud Uploads
Even large multi-hundred megabyte PDFs are divided entirely in browser memory for absolute privacy.
Batch Download as ZIP
Download all resulting partition files in a single organized ZIP package or individually.
Frequently Asked Questions
How does splitting by size work?
The tool measures the byte size of each page stream and groups sequential pages into parts that remain under your target megabyte limit.
Can a single large page exceed the limit?
If a single page exceeds the target limit on its own, it will be placed in its own part at its minimum viable size.
Are files compressed during split by size?
No, splitting by size preserves original quality without recompression unless you choose to compress them separately.
Is this tool free with no limits?
Yes, you can split unlimited files of any size for free.
🔒 100% Client-Side Privacy Guarantee
OM PDF processes all documents entirely in your web browser memory using WebAssembly. Your files are never uploaded to any cloud server, preventing data leakage and guaranteeing total security for confidential documents.