Split PDF by File Size Free Online

Divide large PDF files into smaller parts by size. Split PDF to meet upload size limits. Free online PDF splitter, no signup required.

When a large PDF exceeds an upload portal's file size limit and compression is not sufficient, splitting by size is the practical solution. By dividing the PDF into parts, each segment meets the size requirement individually. Our Split PDF tool lets you select specific page ranges to create each part. To split by size effectively: first estimate the pages per megabyte (divide total pages by total file size in MB), then calculate how many pages fit within your target size. For example, a 50-page 20MB PDF has about 0.4MB per page — so each 5MB chunk would contain approximately 12-13 pages. Image-heavy PDFs have variable page sizes — pages with full-page photos are much larger than text pages. When splitting image-heavy documents, err on the side of fewer pages per chunk to ensure each part stays under the limit. Splitting with a smaller safety margin prevents surprises. For government portals that require multiple attachments, splitting is often preferable to compression because it maintains original document quality. Upload each part as a separate attachment, clearly labeling them "Part 1 of 3", "Part 2 of 3", etc. for the reviewer.