Combine multiple PDF files into one, right in your browser — free, fast and private.
Frequently Asked Questions
Will merging also make the files smaller?
No. Two test files totalling 336.9 KB came out as one 336.0 KB document — the sum of the inputs, minus a few bytes of shared plumbing. Nothing is re-compressed, so nothing degrades and nothing shrinks. If the merged file needs to be smaller, run it through the compress page afterwards, which halved our test document.
Are my PDFs uploaded?
No. Merging runs entirely in your browser. Your files are never sent to a server or stored.
How many can I merge?
There is no hard limit — it depends on your device memory. For many or large files, a desktop browser works best.
Does merging change quality?
No. Merging copies each PDF’s pages into the new file as-is, with no re-compression, so text and selectable content are preserved.
We measured it: real file sizes
Settings: page defaults
Test case
Before
After
Change
mixed + text-only5 + 3 → 8 p
336.9 KB
336.0 KB
−<1%
What the numbers say
Two files totalling 336.9 KB came out as one 336.0 KB document — the merged file is the sum of its inputs, minus a few bytes of shared plumbing. Nothing is re-compressed, so nothing degrades and nothing shrinks either. If you were hoping merging would also save space, it will not: that is what the compress page is for.
Measured on 2026-07-28 by running these files through this very page in Chromium 151.0.7922.34. Every page uses the same published test files, so the numbers are comparable across converters.Method, and download the test images →
What is merging a PDF?
Join several PDF files into one — ideal for combining separate chapters, invoices, scanned pages or reports into a single document that is easy to send and archive. Everything runs locally in your browser with no upload.
How to use it
Select or drop in multiple PDFs.
Check the order (pages follow your selection order).
Click Download for the merged PDF.
Handy tips
Pages are kept as-is — they are not turned into images.
If the merged file is large, run it through Compress PDF.
Only need some pages? Use Split PDF.
The merged file is smaller than its two inputs added together
We merged a five-page mixed document (334.1 KB) with a three-page text-only document (2.8 KB) into eight pages. The inputs sum to 336.9 KB; the output is 336.0 KB — 859 bytes less. The gap is no mystery: every PDF carries its own header, cross-reference table and trailer, and the merged file writes that once instead of twice. So the answer to “will merging compress my images” is no — page content is carried across whole, and the saving is purely file structure. You can check the same number from the other direction: split that document in two and the extracted page plus the remainder come to 334.7 KB, 609 bytes more than the original — the structure written twice. Two tools, opposite signs, the same order of magnitude.
What survives a merge, and what does not
Page order
the order the files appear in the list, page by page
Page content
copied as-is — nothing is re-rendered or re-compressed
Resulting size
roughly the sum of the inputs
The merged file is a newly created document that your pages are copied into. That matters because some things in a PDF live on the pages and some live on the document: page content, its text layer and its own annotations come across untouched, while document-level extras — an outline of bookmarks, an interactive form definition, file-level metadata — belong to the originals and are not part of a page copy. If your sources have bookmarks or fillable fields, open the result and check them before you rely on it.
