Merging PDFs: what you should know
Most online PDF mergers upload your files to a server, combine them there and let you download the result. That is convenient, but it means contracts, invoices, medical letters or ID scans pass through someone else’s computer. ToolCMB works differently: the merging engine runs inside your browser, so your files never leave your device — which also makes it fast, even for large documents.
The pages are copied exactly as they are. Fonts, vector graphics and images are not converted or compressed, so the merged PDF looks identical to the originals and its text remains searchable and selectable. Identical fonts and images that appear in several files are stored only once, which often makes the merged file smaller than the sum of its parts.
Need only part of a document? Type a page range such as 1-3, 7, 10- on a file card, or switch to Pages view to build your document page by page. Images become full pages — sized to A4 or US Letter automatically, or to the size of the image.
ToolCMB vs typical online PDF mergers
| Feature | ToolCMB PDF Merger | Typical online tools |
|---|---|---|
| Files uploaded to a server | Never — runs in your browser | Yes |
| File size / number limits | Only your device’s memory | Often 50–100 MB, 2–20 files on free plans |
| Reorder single pages | Yes, across files | Often premium only |
| Mix images and PDFs | Yes | Usually a separate tool |
| Bookmarks & forms preserved | Yes | Varies |
| Page numbers, uniform page size | Yes, free | Separate tools or paid |
| Sign-up, watermark, daily limits | None | Common |
Tips
- Sorting by name puts 01-intro.pdf, 02-report.pdf … in the right order automatically — numbers are compared naturally.
- Printing double-sided? Turn on Double-sided printing so each document starts on a new sheet.
- Merged file too big for email? Run it through our PDF Compressor afterwards.
- Need the opposite? Use the PDF Splitter to extract pages or split a file into several PDFs.