PDF Tools
PDF Merger
Combine multiple PDF files into one document.
Combine two or more PDF files into a single, cleanly ordered document — right inside your browser, with no uploads to any server. The PDF Merger on FastDailyTools is built for speed, privacy and the kind of everyday workflows freelancers, students, and small teams run into every week.
Use the tool
What this tool does
A PDF merger takes multiple separate PDF documents and stitches them together into one continuous file, preserving page order, fonts, images, links and form data. Our tool runs entirely client-side using the open-source pdf-lib library, so your documents never leave your device. There is no file size cap dictated by an upload limit, no watermark, no signup, and no email harvesting.
Why people use it
- Bundle invoices, receipts and contracts into one file before sending them to a client or accountant.
- Combine scanned pages from a phone scanner app into a single deliverable.
- Assemble a study packet from chapters or lecture notes saved as separate PDFs.
- Compile a multi-section proposal where each contributor wrote their part separately.
- Avoid sending a zipped folder of PDFs that recipients have to extract and open one by one.
Step-by-step guide
- Click ‘PDF Merger’ in the Tools section to open the tool.
- Drag and drop your PDF files into the upload area, or click to browse and select them.
- Reorder the files by dragging — the top file becomes the first pages of the merged PDF.
- Remove any file you added by mistake using the ✕ button next to its name.
- Click ‘Merge PDFs’ — the tool processes everything in your browser.
- Save the resulting merged.pdf to your device. That’s it.
Real examples
Freelancer combining a monthly invoice pack
Maya runs a small design studio and bills four retainer clients each month. She exports each invoice from her accounting app as a separate PDF, then merges them into one ‘October-Invoices.pdf’ before sending the file to her bookkeeper. What used to take a desktop app and a paid subscription now takes 20 seconds in the browser.
Student assembling a thesis appendix
Daniel writes the body of his thesis in Word, but his appendix is made up of scanned questionnaires, lab printouts and reference figures saved as individual PDFs. He drags all of them into PDF Merger in the order required by his university template, downloads the merged file, and attaches it as the appendix to his final submission.
Common use cases
- Legal teams preparing case bundles
- Real estate agents combining contracts and disclosures
- Job seekers merging cover letter, resume and portfolio
- Teachers assembling printable lesson packs
- Anyone who scans receipts for tax season
Frequently asked questions
Are my PDFs uploaded to your servers?
No. The merging happens entirely in your browser using pdf-lib. Your files never leave your device.
Is there a file size limit?
There is no hard limit imposed by us — the practical limit depends on your device’s memory. Most laptops handle hundreds of pages easily.
Will form fields and bookmarks survive the merge?
Form fields are preserved. Bookmarks from the source PDFs are carried into the merged document on a best-effort basis.
Can I rearrange pages before merging?
You can reorder the source files. For full page-level reordering, merge first and then use a page editor.
Is this tool really free?
Yes. Every tool on FastDailyTools is 100% free with no signup, no trial and no watermark.