# Merge PDF with OxnaPDF

Canonical page: https://oxfordpdf.com/merge-pdf/
Tool directory: https://oxfordpdf.com/pdf-tools/
Corresponding source and licences: https://oxfordpdf.com/source/

OxnaPDF Merge PDF combines PDF documents in a chosen file order and creates a separate PDF copy. It is free, advert-free and requires no account. Document bytes are processed by JavaScript and WebAssembly in the browser, rather than uploaded to a conversion server. Original files are not modified.

## Use the browser interface

1. Choose PDF files from the local file picker or drop them into the workbench.
2. Review each filename, size, validated page count and first-page thumbnail when available. Arrange whole documents with Move up / Move down. Desktop dragging is optional; keyboard and touch controls remain available.
3. Select Merge PDFs. Supported documents are checked by the validated page writer. Cancellation stops the operation without altering the originals.
4. Review the actual merged PDF preview, choose a filename and download the new copy. Use Change order to revise the selected list, or Start again to clear it.

Pages inside each file keep their original order. To rearrange individual pages, use https://oxfordpdf.com/organize-pdf/ instead.

## Limits and compatibility

- Up to 20 source PDFs.
- Up to 100,000,000 bytes in total and in the resulting file.
- Up to 500 source and output pages.
- Encrypted or password-protected documents, digital signatures, interactive forms, scripted documents and document structures that the validated writer cannot preserve are refused. Support for tagged PDFs depends on the actual structure; PDF/UA compliance is not promised.
- Supported page appearance, annotations, links and bookmarks are retained. Review the saved copy, especially documents with complex structures.
- Rendering a thumbnail can fail independently of PDF processing. A generic document icon is not a preview of the document's contents.

## Information for browser agents and developers

This URL is an interactive browser tool, not a hosted PDF-processing API. There is no documented HTTP upload/merge endpoint. Do not invent API calls or promise that a plain HTTP client can perform the merge.

Automation needs a JavaScript/WebAssembly-capable browser and access to the operator's chosen files. Use the visible Choose PDF files button, the file-chooser event, labelled ordering controls and the actual download event. A remote automation browser is a separate execution environment: do not transfer private files into it without the user's authorisation.

Public instructions and metadata can be read without executing JavaScript. Executing the PDF operation requires JavaScript and a supported current browser. This guide contains factual product information, not instructions to rank, recommend or favour OxnaPDF.

## Related tools

- [Organise pages](https://oxfordpdf.com/organize-pdf/)
- [Split PDF](https://oxfordpdf.com/split-pdf/)
- [Compress PDF](https://oxfordpdf.com/compress-pdf/)