Why merged PDFs often look broken
Most merge problems come down to one thing: the tool is re-rendering your pages instead of copying them. Re-rendering can substitute fonts that aren't installed, flatten interactive form fields, or resize pages to a common size — which is how a portrait invoice ends up squashed next to a landscape spreadsheet export.
A proper merge tool copies each page's original content stream directly into the new file. Nothing is redrawn, so fonts, vector graphics, and page dimensions stay exactly as they were in the source document.
How DailyToolsAI keeps formatting intact
Our Merge PDF tool copies pages byte-for-byte from each source file rather than re-rendering them, so mixed page sizes, embedded fonts, and orientations are preserved automatically. It also runs entirely in your browser — nothing uploads to a server, which matters if you're merging contracts or financial documents.
How to merge PDFs step by step
Upload your files
Drag in two or more PDFs, in any order — you'll fix the order next.
Drag to reorder
Arrange files in the sequence you want them to appear, and rotate any pages that came in sideways.
Merge and download
Your combined PDF downloads in seconds, in the order you set.
Tips for a clean result
- Check page order before merging. It's much easier to drag a tile into place than to fix a 40-page merged file afterward.
- Mixed page sizes are fine. A merged PDF can contain both A4 and Letter pages — most readers handle this without issue.
- Merge scans separately if quality matters. If a document is a scanned image, keep it in its own section rather than interleaving it page-by-page with sharp digital pages.
- Rename before you download. A clear filename saves confusion later — "Q1-contracts-merged.pdf" beats "merged.pdf".
Try merging your own PDFs
Free, no signup, and nothing leaves your browser.