Merge PDF
Add two or more PDF files. Use the ▲/▼ buttons to set their order, then merge and download. Processing stays on your device; time and file limits depend on available memory.
Drop PDF files here or click to choose
Add 2 or more PDFs. Use the arrows to reorder before merging.
Try it with sample files
Combine a document and its attachment in the right order
Use a two-page document and a one-page attachment to check the page order and mixed page sizes before merging your own files.
Settings and steps
- Download both samples, then add them to the file area above.
- Use ▲/▼ beside the filenames to put sample-a.pdf first and sample-b.pdf second.
- Select “Merge PDFs” to download merged.pdf.
Expected result and checks
One PDF with three pages: A1 → A2 → B1. The different page sizes are retained.
Download reference output · merged.pdf ↓- Read the page labels: “sample-a - page 1”, “sample-a - page 2”, then “sample-b - page 1”.
- Check that A2 remains smaller than A1. Merging does not resize every page to A4.
Limits and troubleshooting
- The button needs at least two PDFs. This tool appends whole files; extract selected pages first if an attachment contains pages you do not want.
- If a large batch fails, try fewer files. These samples do not establish preservation of bookmarks, interactive forms or valid digital signatures; check those features separately.
Reference results recorded: · View check record (JSON)
Merge appends every page in file-list order. If A has two pages and B has one, adding A before B produces A1, A2, B1. Use Split first to keep only selected pages, or Organize PDF to rearrange individual pages. Open the result to check its page count and content, and keep your originals.
How to Merge PDF
- Drop in two or more PDF files you want to combine.
- Use the ▲/▼ buttons beside each file to set the order.
- Select Merge PDFs to download merged.pdf, then check its page order.
Frequently asked questions
Are my PDFs uploaded to a server?
The merge operation reads and processes the selected PDFs on your device without uploading them. The webpage may still connect to download processing components and load other site services; local document processing does not mean the whole page is offline.
Is there a limit on how many PDFs I can merge?
The tool does not set a fixed file count or size cap. Available device memory, browser limits and document complexity affect what can be processed. If a large batch fails, try fewer files and check each result.
Can I change the order of the files before merging?
Use the ▲/▼ buttons beside each file to set the order.
Does merging reduce the quality of my PDFs?
Page content is copied without deliberately recompressing images. Do not assume bookmarks, interactive forms, accessibility tags or digital signatures are preserved; keep the originals and inspect the output.
Can I merge PDFs on my phone or offline?
This tool processes your document on your device without uploading it. It may download the components needed to run.
Can I merge PDFs with different page sizes or orientations?
Yes. Pages are copied with their original sizes and rotation settings, so an A4 page and an A3 page can appear in the same output. They are not resized to match. Check the result in your PDF reader and review the print settings before printing mixed page sizes.
Can I merge password-protected or encrypted PDFs?
This tool has no password field and does not decrypt encrypted page contents. Start with an unencrypted copy that you can open, or unlock it using the password before merging. The site's Remove Password tool uploads the file to a server; check the processing notice before using it. Keep the encrypted original.
How do I merge only certain pages instead of whole files?
Split or trim the source documents first. Use Split PDF to pull out the page ranges you want, then merge the resulting files. Alternatively, run Organize PDF on a copy to delete the pages you do not need before merging. Merging itself always appends complete files, so any trimming has to happen before the merge step.
Does merging change the file size or compress my images?
The merge operation copies pages without deliberately recompressing their images, but it writes a new PDF, so the output size need not equal the sum of the inputs. Check the downloaded file size. Compress PDF can be a separate next step if needed; it uploads the file and may reduce image detail.
Can I merge large batches of PDFs, and is there a file limit?
Larger batches can need more memory and processing time. On phones and low-memory devices, try smaller groups if the operation fails or becomes unresponsive. Keep the originals and check the page count and content of every output before using it.
📖 How to Merge PDFs in the Right Order, with a Worked Example →
Try the tools with sample files
Download sample files, compare page order, rotation and compression outputs, and understand processing limitations.
See checks and sample files →
