Merge PDF
This tool combines two or more PDF files into a single document, entirely in your browser. Drop your PDFs, arrange them in the exact order you need, and download the merged result as one file. Nothing is uploaded to a server: the merging is done locally by the pdf-lib library, so your documents stay on your device from start to finish.
100% in your browser. Your file never leaves your device.
Features
- Combine any number of PDF files into one document in a single step.
- Drag and drop the file list to set the exact merge order.
- A first-page thumbnail next to each file helps you check the order.
- All pages keep their original quality — nothing is re-rendered or recompressed.
- Runs completely in your browser; files are never uploaded to a server.
- Works on desktop, tablet and phone without installing any software.
About this tool
When you add files, each PDF is read straight from your device into browser memory. The open-source pdf.js library renders a small preview of the first page, so you can tell similar-looking files apart. The list itself stays fully editable: drag entries into a new order, remove single files with the × button, or add more at any time.
The merge itself is handled by pdf-lib, a JavaScript PDF library running locally in your browser. It creates a fresh, empty PDF and copies every page of each source file into it, in the order shown in your list. Because pages are copied rather than re-rendered, text, images and vector graphics keep their original resolution and quality.
The finished document is assembled in memory and offered as a download named merged.pdf — at no point does any data leave your device. Since everything runs client-side, the practical limit is your browser's memory: merging many large scans on a low-end phone can be slow or fail, while typical office documents merge in seconds.
How to merge PDFs
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Add your PDF files
Drag two or more PDFs onto the dropzone, or click "Choose file" and select several files at once (hold Ctrl or Cmd while clicking). The files appear as a list showing each name and file size.
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Check the thumbnails
Each entry shows a small preview of its first page next to the file name and size. Use these thumbnails to confirm you picked the right documents before you start the merge.
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Arrange the merge order
Drag entries up or down — files are merged from top to bottom. If dragging doesn't work on your touchscreen, remove files with the × button and re-add them in the desired order via "Add more files".
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Start the merge
Click "Merge & download". pdf-lib now copies all pages of every file, in list order, into one new document. This happens locally on your device; large files may take a few seconds.
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Save the merged PDF
Your browser downloads the result as merged.pdf, or asks where to save it, depending on your settings. The original files remain untouched on your device, and the tool resets for the next merge.
Typical use cases
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Application documents in one file
Many job portals accept only a single attachment per application. Instead of sending cover letter, CV and certificates as separate files, merge them into one PDF in the order the recruiter should read them. Since your personal documents never leave your device, this is a comfortable option for sensitive records too.
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Bundling scans and receipts
Scanners and phone apps often produce one PDF per page or per receipt. Before filing your monthly expenses or sending records to your accountant, drop all the individual PDFs here, sort them chronologically using the thumbnails, and download one tidy document instead of a dozen loose files.
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Assembling reports from several sources
A final report often consists of parts made in different programs by different people: a title page from a design tool, chapters from a word processor, an appendix of spreadsheets. Export each part as PDF and merge them here in the right order — you hand over one continuous document without touching any layout.
Tips & limitations
- Bookmarks and the clickable table of contents of your source files are not carried over — pdf-lib copies pages, not document-level navigation. Recreate important bookmarks afterwards in a PDF editor.
- Interactive form fields can lose their function when pages are copied into a new document. If a source PDF contains fillable forms, fill them out and flatten them before merging.
- The whole merge runs in browser memory. When combining many large scans, close other tabs first or merge in batches — on phones especially, memory runs out sooner than on desktops.
- Only need some pages of a file? Extract them first with the Split PDF tool, then merge the extracted part here — this tool always takes every page of each file.
Frequently asked questions
Are my PDF files uploaded to a server?
No. The files are only read into your browser's memory and processed there by pdf-lib. You can verify this yourself: open your browser's network tab while merging — no file data is transmitted.
How many PDFs can I merge at once?
The tool itself sets no fixed limit. The practical limit is your device's memory, because every file is held in RAM during the merge. Dozens of normal documents are fine; hundreds of large scans may fail, especially on mobile devices.
Does merging reduce the quality of my pages?
No. pdf-lib copies the original page contents unchanged — text, fonts, images and graphics are neither re-rendered nor recompressed. The merged file is roughly the sum of the input sizes; if it ends up too large, use the Compress PDF tool afterwards.
Are bookmarks and links preserved?
Bookmarks (the document outline) are not carried into the merged file — a limitation of the page-copy approach. Links that sit on a page itself usually keep working, but links pointing to other pages of the document can break.
Can I merge password-protected PDFs?
Partly. Files that only restrict printing or editing but open without a password are loaded with encryption ignored and usually merge fine. PDFs that require a password just to open cannot be processed reliably — remove the protection first.
Can I pick individual pages from each file?
Not in this tool — it always merges all pages of every file, in list order. If you only need certain pages, run the file through the Split PDF tool first and then merge the extracted pages here.
What is the merged file called and where does it end up?
The suggested name is merged.pdf. Depending on your browser, it lands in your Downloads folder or a save dialog lets you choose location and name. Your original files stay untouched on your device.
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