How to Merge PDF Files Into One (Free, Private)

Combining PDFs is one of the most common reasons to reach for an online tool, and one of the worst reasons to upload files, because the documents being merged are often the ones you least want on someone else’s server: contracts, statements, application packs. PDFkitt merges files inside your browser and the combined PDF is generated on your device.

Merge several PDFs at once

1. Select all the files. On the home page, drag two or more PDFs onto the upload card at the same time, or click the card and select several files in the picker (hold Ctrl or Shift).
2. Let them open. The files are combined in the order you selected them into a single document. A progress bar shows large files loading.
3. Check the order in the pages panel. Click the pages button in the toolbar (the panel icon on the left) to show thumbnails. Drag a thumbnail up or down, or use the arrow buttons under it, to reorder.
4. Tidy up. Delete pages you do not need (bin icon), rotate any that are sideways, or insert a blank page as a separator.
5. Download. Click Download, give the combined file a name, and click Download PDF.

Add a PDF to a document that is already open

1. Open the pages panel. Toolbar → pages button.
2. Click Merge PDF. Choose the file to add. Its pages are appended at the end of the document.
3. Move the new pages where they belong. Drag thumbnails, or tick several with their check boxes and use the arrows.
4. Download. All page operations are undoable with Ctrl+Z if something goes wrong.

Tips

• Mixed page sizes are fine. A4 and Letter pages, or portrait and landscape, can live in the same document; each page keeps its own size.
• Only need some pages of a file? Merge the whole file, then delete the pages you do not want; or open that file first, extract the pages you need to a new PDF, and merge that. See splitting and extracting.
• Forms. Fillable fields in merged files are kept interactive when the page layout is unchanged; after reordering or deleting pages their values are flattened into the page (they still display, but can no longer be edited).
• Large merges. There is no page limit, but everything is held in memory. A few hundred pages is comfortable on most laptops; very large image-heavy scans may be slow on phones.

Frequently asked

Can I merge a Word document or an image with a PDF?

Not directly. Save the Word document as PDF first (File → Save as → PDF). An image can be placed on a blank page: pages panel → Blank page, then Insert → Image. See adding images.

Does merging reduce quality?

No. Pages are copied as they are, without re-rendering, unless you tick Compress on download.

Is there a file size limit?

No hard limit, because there is no upload. The editor warns you above 20 MB simply because rendering may take longer on slower devices.