Merging PDFs combines multiple files into one document with a single page sequence. It takes about 30 seconds when you use a tool that handles the processing server-side.
When you need to merge PDFs
The most common scenarios: combining an invoice and its payment receipt for accounting records, stitching multiple scanned pages into one file because your scanner outputs one PDF per page, or assembling chapters from separate sources into a single submission document.
Any situation where you are emailing or uploading several PDFs as a set and the recipient expects one file is a merge situation. A merged file is also easier to archive, sign, or watermark in a subsequent step.
How to merge PDF files online
Open the PDF merger and upload your files. You can upload them one at a time or select multiple files at once from the file picker. The upload limit is 20 MB per input file.
Once uploaded, click Merge. The tool processes the files server-side, combines them in the order they were added, and gives you a download link for the merged result. Files are deleted from the server after processing — they are not stored or accessible after your session.
Controlling the page order
The output page order matches the upload order. The first file you upload becomes the first pages of the merged document, the second file follows, and so on. Upload your files in the exact sequence you want them to appear in the final PDF.
If you uploaded files in the wrong order, remove them and re-upload in the correct sequence. There is no drag-to-reorder step after upload — sequence control happens at the upload stage.
File size and limits
Each input file can be up to 20 MB. The output file size is approximately the sum of the input sizes — PDF merging does not apply additional compression to the content. Images embedded in PDFs remain at their original compression level.
If your merged output is too large to email, convert image-heavy pages to lower-resolution JPGs first using PDF to JPG, then reassemble. Alternatively, if the merged file contains pages you do not need, use split PDF on the output to remove them.
When to split instead of merge
If you have one large PDF and need to extract specific pages — for example, pulling pages 3–7 out of a 40-page report — use split PDF instead. Splitting does not require a merge step; it extracts the page range you specify directly from the source file.
For documents that need a watermark on every page (draft notices, confidential labels), apply the watermark after merging using watermark PDF. Applying the watermark post-merge is more efficient than watermarking each file individually before combining them.
Getting a clean merged PDF
Upload in order, stay within the 20 MB per-file limit, and download immediately after processing. The tool handles the page stitching without altering the content of individual pages — formatting, fonts, and embedded images carry over exactly from the source files.
For multi-step PDF workflows — merge, then extract pages, then add a watermark — the PDF merger, split PDF, and watermark PDF tools work in sequence with no account or software installation required.