Merge PDF

Combine multiple PDF files into a single document, right in your browser.

Maximum file size: 50 MB for guests

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About the Merge PDF tool

The Merge PDF tool combines two or more PDF files into a single document in the exact order you choose. Everything happens inside your browser, so your files never leave your device — there is no upload, no server-side copy, and no waiting in a queue.

This is ideal for assembling scanned receipts into one report, joining chapters into a full book, or consolidating contract pages before sending them to a client. The merged PDF preserves the original pages, orientation, and embedded text exactly as they were in the source files.

Combining PDFs in the browser rather than through an upload service matters most when the documents are confidential — legal filings, medical records, financial statements, or internal reports that should not sit on a third-party server even briefly. Because the merge happens on your own machine, you can assemble sensitive material with the same confidence as moving files between local folders.

The tool accepts any mix of PDF versions and page sizes in a single batch, so you can stitch a letter-size contract onto an A4 appendix without manual adjustment. The output is a standard PDF that opens in every reader — Adobe Acrobat, Preview, Foxit, and browser viewers alike — with bookmarks and links from the source files preserved where present.

How to use Merge PDF

  1. 1Click the file input and select two or more PDF files. You can pick them in the order you want them to appear.
  2. 2Review the numbered list to confirm the merge order. Remove and re-add a file if you need to change it.
  3. 3Press the merge button. The tool reads each PDF in your browser and assembles a new combined document.
  4. 4The merged PDF downloads automatically as merged.pdf. Open it to verify the page order before sharing.

How the browser-based processing works

Merge is powered by pdf-lib, a pure-JavaScript PDF library that runs inside the browser without a server. When you press merge, the tool loads each selected PDF into memory, iterates over the page tree of every document, and copies the page objects — including content streams, fonts, and embedded images — into a fresh PDF package. No page is re-rendered or re-encoded, so the visual output is identical to the source pages.

Because the operation copies existing page objects rather than re-distilling the document, merge is both fast and lossless. The only limit is available device memory: a batch of very large PDFs needs enough RAM to hold every source file plus the output at once. Free accounts can process files up to 250 MB each, with no artificial cap imposed by Convert26.

The output downloads instantly as merged.pdf once assembly completes. If a source PDF is password-protected, unlock it first with the Unlock PDF tool so the page tree can be read. For rearranging pages within a single document rather than joining separate files, use Split PDF to break it apart, then Merge PDF to reassemble in the desired order.

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