Merge PDF

We use pdf-lib, an open-source JavaScript library, to read and combine PDF files in your browser. Coda One does not upload the files during the merge flow, so you can move from upload to download in one direct PDF workflow.

There is no fixed page or file-count gate in the page flow, but very large files can slow down depending on your device memory and browser performance.

Yes! After adding your files, drag and drop them to change the order. The final PDF will follow the order you set.

Yes. Files are processed in your browser using JavaScript and are not uploaded to our servers. We do not receive the PDF contents during the merge flow.

Encrypted PDFs are loaded with the ignoreEncryption option, which allows merging the page content without requiring the password. However, the merged output will not be encrypted — existing restrictions are removed. If you need the merged file to be password-protected, use our PDF Protect tool after merging.

There is no hard limit on the number of files. In practice, merging very large numbers of files (50+) or files with many pages each may use significant browser memory. If the tool becomes slow or unresponsive, try merging in smaller batches and then merging the results.

Yes. The tool runs entirely in your browser, so it works on any modern mobile browser (Safari, Chrome, Firefox). Drag-and-drop reordering is supported via touch gestures.

Adobe Acrobat is a broader paid PDF suite with desktop and cloud workflow options. Coda One focuses on browser-first merging without uploading files to our servers.

Yes. Each page retains its original dimensions. If one file is A4 and another is US Letter, the merged PDF will contain both sizes as-is.

After merging, use our <a href="/compress-pdf">PDF Compressor</a> to reduce the file size. Image-heavy PDFs often benefit from a follow-up compression pass before sharing or archiving.

Yes. Use our <a href="/split-pdf">PDF Splitter</a> to extract specific pages or split the merged document back into separate files.

Page content, annotations, and internal links within each source file are preserved. Top-level bookmarks (table of contents) from individual files may not be merged into a unified outline.

Any modern browser: Chrome, Firefox, Safari, Edge, and Brave. We use pdf-lib which relies on standard JavaScript APIs. Internet Explorer is not supported.

Yes. Scanned PDFs merge the same way as digital PDFs. If your scans are image-heavy, merge them first and then run the result through <a href="/compress-pdf">PDF Compressor</a> to keep the final file manageable.