Merge PDF

How it works

This tool turns merging into a visual editor rather than a blind file-order guess. Drop one or more PDFs and every page from every file appears as its own thumbnail in one shared grid, in the order the final document will have — not grouped by file, but interleavable exactly as you drag them. The actual merge happens in a background Web Worker only once you click Merge, so the page never freezes while you rearrange things.

Each thumbnail carries a small colored badge naming its source file and original page number, and every loaded file gets its own color, so once you've mixed pages from several PDFs together you can still tell at a glance where each one came from. Hover a card (or just tap it on a phone) to reveal its controls: drag the grip to reorder, ⟲/⟳ to rotate that page in place, ⧉ to duplicate it, or × to drop it from the final document. "Rotate all" and "Reset order" above the grid apply to every page at once.

Large PDFs render progressively: only the thumbnails currently on screen are decoded, a few at a time, so dropping a 100-page file doesn't lock up the tab — scrolling further down renders more as they come into view. Your original files are never modified, and nothing you upload here ever leaves your device.

Under the hood, each page's content stream, fonts, and embedded images are copied byte-for-byte from the source PDF into the new one — nothing is rasterized, re-rendered, or recompressed. That means the merged file looks exactly as sharp as your originals, and any selectable or searchable text stays selectable and searchable in the result, unlike merging tools that flatten pages to images.

Limitations

Password-protected PDFs aren't supported directly — you'll see which files were skipped and a link to unlock them first, and the rest of your batch still loads normally. Bookmarks (the outline/table of contents) from the source files aren't preserved in the merged result, and form fields with matching names across different source PDFs may end up linked together, showing the same value in both places — both are limitations of how PDF merging works at a structural level, not something this tool chooses to skip. There's no limit on the number of files or pages you can merge; the only real ceiling is your browser's available memory, which comfortably handles documents into the hundreds of pages.

Combining scanned documents

Merging scanned PDFs works the same as merging any other PDF, but it's worth being clear about what "scanned" means for the result. A scan is already just an image per page — there's no text layer to begin with, so merging several scans together doesn't lose anything that was there, and it doesn't add a text layer either. If your source PDFs were created from real documents (Word exports, e-signed contracts) rather than a scanner, any selectable text they already had is preserved untouched, because merging copies each page's underlying content stream rather than re-rendering it.

On file size: merging N scanned PDFs produces a result roughly as large as the sum of the originals — merging doesn't re-compress the embedded images, it just combines the page objects, so a 10 MB scan plus another 10 MB scan comes out around 20 MB, not smaller. If the combined file needs to shrink for an email attachment limit, that's a separate step; extracting an image-heavy PDF's pages and running them back through PDF to JPG at a lower DPI is one practical way to cut it down.

FAQ

Is this PDF merger really free?

Yes — completely free, with no file count or size limits, and no account required. Everything runs in your browser, so there's no server cost to recoup.

Can I see which file each page came from?

Yes — every page thumbnail shows a small colored badge naming its source file and original page number, and pages from the same file share a color, so a big mixed grid stays easy to read.

Can I reorder, rotate, duplicate, or remove pages before merging?

Yes — drag any thumbnail to a new position, click ⟲/⟳ to rotate just that page, ⧉ to duplicate it, or × to leave it out entirely. The grid always shows exactly what the final document will look like.

Are bookmarks (the outline/table of contents) preserved?

No — merged PDFs don't carry over the original bookmarks from each source file. This is a real limitation of the underlying library, not something we chose to skip; if you rely on bookmarks, add them back afterward in a PDF editor.

What about PDF forms with fields of the same name in different files?

If two source PDFs both have a form field with the same name (for example, both have a field called "Name"), most PDF viewers will treat those as one logical field and show the same value in both places after merging. This is a known edge case with programmatic PDF merging in general, not specific to this tool.