Drop PDF files here or click to browse
Select multiple files to combine into one PDF
Drop files to add
Files (0)
Preview merged order
Merging files...
0%
Merge Complete
Files processed locally — never uploaded
Also try: AI Humanizer · Summarizer · Rewriter 3 free uses/day
How It Works
1
Upload PDFs
Drop or browse for PDF files. Add as many as you need — no limits.
2
Drag to reorder
Arrange files in the exact order you want. The merged PDF follows your sequence.
3
Merge & download
Click merge and download instantly. Everything happens in your browser.
FAQ
How does PDF merge work in the browser?
We use pdf-lib, an open-source JavaScript library, to read and combine PDF files entirely in your browser. No files are uploaded to any server — everything happens locally on your device.
Is there a file size limit?
There is no hard limit, but very large files (100MB+) may be slow depending on your device's memory. Most users can merge dozens of files without issues.
Can I reorder pages before merging?
Yes! After adding your files, drag and drop them to change the order. The final PDF will follow the order you set.
Is my data safe?
Absolutely. Your files never leave your device. All processing happens in your browser using JavaScript. We cannot see or access your files.
What happens if I try to merge an encrypted or password-protected PDF?
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.
How many files can I merge at once?
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.
Can I merge PDFs on my phone or tablet?
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.
How is this different from Adobe Acrobat?
Adobe Acrobat requires a paid subscription and uploads files to Adobe servers. Coda One merges PDFs locally in your browser for free — no account, no upload, no subscription.
Can I merge PDFs with different page sizes?
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.
What if I need to compress the merged file?
After merging, use our <a href="/ai/pdf/compress">PDF Compressor</a> to reduce the file size. Image-heavy PDFs often see 40-70% reduction.
Can I split a merged PDF later?
Yes. Use our <a href="/ai/pdf/split">PDF Splitter</a> to extract specific pages or split the merged document back into separate files.
Does merging preserve bookmarks and links?
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.
What browsers are supported?
Any modern browser: Chrome, Firefox, Safari, Edge, and Brave. We use pdf-lib which relies on standard JavaScript APIs. Internet Explorer is not supported.
Do more with your documents
Summarize, rewrite, or translate the text in your PDFs with AI.
Coda One's PDF Merger combines multiple PDF documents into a single file entirely in your browser. No upload, no server — everything processed locally with pdf-lib.