PDF Merger

How to use

1. 1Drop two or more PDF files onto the upload zone, or click Add PDFs to pick them. You can add up to 20 files, 200 MB each, and 500 MB combined.
2. 2Use the Up and Down buttons next to each file to put them in the order you want them to appear in the merged document.
3. 3Type a name for the merged file (defaults to merged.pdf). The name is sanitized to a safe file name on download.
4. 4Click Merge to build the combined PDF. The output is generated in your browser and reported with a total page count and object count.
5. 5Click Download to save the merged .pdf to your device. Files that could not be parsed (encrypted, or with object streams) stay in the list with a clear message so you can swap them out.

About this tool

PDF Merger combines multiple PDF files into a single PDF, in the order you choose, entirely inside your browser. Drop two or more files, drag them into the order you want, and click Merge: a new PDF appears for download with every page from every file in one continuous document. Nothing is uploaded. The files are read with file.arrayBuffer(), the page objects from each PDF are walked from the document catalog through the /Pages tree, every reachable resource (fonts, images, color spaces, content streams, page-level annotations) is collected, every object is renumbered into a unified global space, indirect references are rewritten so the merged file is internally consistent, and the output is emitted with a fresh /Type /Catalog plus /Type /Pages root plus a clean cross-reference table and trailer. Stream payloads (the binary content of fonts, images, and page contents) are copied byte-for-byte so the visual fidelity of each page is preserved. The tool works on PDFs that use the classical cross-reference table layout, which covers the overwhelming majority of PDFs produced by word processors, design tools, browsers, scanners, and report generators. PDFs that store their catalog entirely inside compressed object streams (PDF 1.5+ /Type /ObjStm) and password-protected PDFs are detected and reported per file so you can re-save without object streams or remove the password in a desktop reader. Outlines (bookmarks), document-level metadata, structure tree, named destinations, and form fields are not carried over, but per-page annotations (highlights, comments, link rectangles) that live inside the page dictionary stay attached to their pages. Useful for combining contracts and addenda, stitching scanned receipts into one expense report, joining a cover letter and a CV, building a single course pack from chapter PDFs, or assembling exported invoices into one monthly bundle. Because everything runs locally, contracts, financial documents, medical records, and any other private material you would rather not upload to a third-party SaaS stay on your device.

Free to use. Works in your browser. No signup, no login.