Merge PDF File Order and Size Limits

File-level order is not page-level order

Each row in the merge list is one PDF. Moving that row moves every page inside that file together. Pages already inside File A keep their internal sequence; Merge PDF does not interleave page 2 of File A with page 1 of File B.

If you need individual pages from different documents mixed together, extract or organize those pages into the files you want first, then merge the prepared PDFs. Organize PDF reorders pages inside one document; Merge PDF only orders whole documents.

Move up, Move down, Remove, and Clear

After you add PDFs, the numbered list shows merge order from top to bottom. Use Move up or Move down to change a file’s position. Use Remove to drop one file while keeping the rest. Use Clear to empty the entire selection and start over.

The tool also shows each file’s size and page count, plus a running total of bytes and pages. There is no separate page-count ceiling—only file count and size limits—so a packet can grow tall in pages while still fitting under 50 MB if the files are light.

• Move up / Move down: change which whole file comes first.
• Remove: delete one file from the list.
• Clear: reset the entire selection.
• Pages inside each PDF keep their original internal order.

When to use Organize PDF around a merge

Organize before merging when one source has upside-down scans or a wrong chapter order. Organize after merging when the combined packet needs a final page shuffle. Do not expect Merge PDF itself to provide those page controls.

Exact count and size limits

You need at least two PDFs and may select up to twenty. Each file can be up to 25 MB. All selected files together must stay at or under 50 MB. There is no explicit maximum page count on Merge PDF.

Jobs still fail when compressed scans push the combined size over 50 MB even if each file looks “small.” Reduce image-heavy PDFs, split oversized sources, or remove unused files before merging again.

• Minimum: 2 PDF files.
• Maximum: 20 PDF files.
• Per file: 25 MB.
• Combined total: 50 MB.
• Page-count cap: none (size and file count still apply).

Password-protected or encrypted PDFs are unsupported. Unlock them before merging. Corrupt files fail inspection and should be repaired elsewhere.

Output and processing model

A successful merge downloads one file named merged.pdf. Processing runs in the browser with pdf-lib; PDF contents are not uploaded to Looty Tools for this workflow. For privacy details beyond limits and ordering, read the companion guide on merging without uploading.