Contract plus signed addendum
You signed a master agreement last quarter and just received an addendum with the new payment terms. Drop both files in, addendum second, and you have one cohesive contract instead of two attachments to email.
Merge PDF
Merge PDFs entirely in your browser
No uploads. No waiting. No watermarks. Filoraio is a free PDF merger that combines your files directly on your device — your documents never reach our servers.
Last reviewed ·by the Filoraio team
- Runs entirely in your browser
- No file uploads
- No account required
How your file moves
Your document never leaves this tab.
Filoraio runs the merge directly inside your browser using a small WebAssembly engine. Nothing is uploaded, nothing is queued, and you can verify it yourself — open your browser’s DevTools, switch to the Network tab, and watch it stay quiet.
- 01
You pick the files
They’re read into your browser’s memory through a standard file picker.
- 02
Your CPU does the work
The merge runs locally — no request leaves your device while it processes.
- 03
You save the result
The combined PDF lands in your downloads folder, the same way any other download would.
- 04
Network stays asleep
No upload bar, no progress spinner waiting on a server. Works offline once the page is loaded.
Step by step
How to merge PDFs in four steps
From upload to download takes well under a minute, even with a dozen documents and hundreds of pages.
Add your files
Drag PDFs onto the drop area or click to pick them from your computer. There's no cap on how many you can include in a single session.
Reorder if needed
Each file becomes a numbered card. Move cards up or down to control which pages come first in the final document.
Combine in your browser
Press the merge button. The work runs locally on your device using WebAssembly — nothing is uploaded, nothing is queued.
Save the result
A single PDF downloads to your machine. Page sizes, fonts, and embedded images stay exactly as they were in the originals.
Who it’s for
Who uses Filoraio to join PDFs
If your work involves collecting paperwork from different sources and handing it over as one clean document, this is the tool you'll come back to.
Legal teams
Assemble exhibit bundles, briefs, and signed addenda into a single filing-ready PDF.
Students
Turn chapter scans, lecture slides, and your own notes into one study packet for a tablet.
Accountants
Roll up monthly invoices, receipts, and bank statements into a quarterly close package.
Realtors
Bundle the listing sheet, floor plan, and photo gallery into one document buyers can save.
HR & operations
Stitch the offer letter, NDA, and benefits guide into a single welcome packet for new hires.
Freelancers
Combine a proposal, scope-of-work, and references into one polished PDF to send to clients.
In practice
Real situations this tool solves
Three quick walkthroughs of the exact problem most people are trying to fix when they search for a way to put PDFs together.
Scanner that saved each page separately
Some flatbed scanners output one PDF per page. Add the pages in numerical order and the result reads as a single continuous document — much easier to read and archive than a folder full of fragments.
Tax season paperwork
Combine your W-2, 1099s, last year's return, and supporting receipts into one PDF you can send to your accountant or upload to a tax portal in a single click.
Multi-author research paper
Each co-author drafted their section as its own PDF. Merge them in section order and the final paper is ready for review without anyone having to copy-paste between Word documents.
Pro tips
Tips for cleaner merged PDFs
Four small habits that turn a good merge into a perfect one — useful whether you're combining two contracts or fifty scanned forms.
Match page sizes before you merge
Mixing A4 and US Letter inputs produces a PDF where pages alternate sizes — visible as a slight jitter when scrolling. If consistency matters, convert all sources to the same paper size first.
Reorder before merging, not after
Drag the cards into their final order on this page. Reordering pages inside a merged PDF later requires a separate page editor — much more work than getting the input order right up front.
Watch for blank pages from scanners
Multi-page scanners often add a blank page at the start or end of each scan. Spot them in the page count, then use our Remove Pages tool on the merged result to drop them in one pass.
For huge merges, close other browser tabs
The merge runs in your browser's memory. Combining 50+ large scans on a low-RAM device can stall — closing other tabs frees the headroom Filoraio needs to finish quickly.
How it compares
How Filoraio's merger compares to typical online tools
Side by side with the average online PDF merger — including the ones with millions of monthly users.
| Feature | Filoraio | Typical online PDF tools |
|---|---|---|
| Where files are processed | On your device | Uploaded to servers |
| Watermark on output | None | Often added on free tier |
| Account required | No | Often required for full access |
| File size limit | None — your device's RAM | Usually 25–100 MB |
| Daily usage cap | Unlimited | Often 2–5 merges per day |
| Works offline | Yes (after first load) | No — requires server roundtrip |
Questions
Common questions about Merge PDF
Quick answers to the things people ask most often before using this tool.
Is this PDF combiner really free, with no catch?
Yes. There's no signup, no trial period, no daily limit, and nothing watermarked on the output. Filoraio is supported by unobtrusive ads on the page — never on your file.
Are my documents uploaded somewhere?
No. The merge runs entirely on your device using a small WebAssembly library. Your PDFs never leave the browser tab, which is why this works offline and on confidential files.
How many files can I join in one go?
There's no hard cap. Most browsers handle 50+ documents with thousands of pages without trouble — the only practical limit is your device's available memory.
Can I change the page order before exporting?
Yes. Each file appears as a card you can move up or down. The number badge on each card reflects exactly where its pages will land in the final document.
What happens to bookmarks, hyperlinks, and form fields?
Internal links, named destinations, and form fields are carried over from each source PDF. External hyperlinks remain clickable. Bookmarks from each input are preserved as a nested outline in the output.
Will the combined PDF be smaller than the originals added up?
Usually it's nearly identical to the sum of the parts. If you want a smaller file afterwards, run the result through our Compress PDF tool — that's the right step for shrinking, not merging.
Can I include a password-protected PDF?
Not directly — encrypted PDFs need to be unlocked first. Our Unlock PDF tool removes owner restrictions automatically and decrypts password-protected files locally when you supply the password, then this merge tool handles the rest. We never bypass passwords you don't have.
Does this work on a phone or tablet?
Yes. The interface is fully touch-friendly on iOS and Android, and because the heavy lifting happens locally there's no upload speed bottleneck on a mobile network.
How do I merge PDFs on a Mac without using Preview?
Open this page in Safari or Chrome, drag your PDFs in, and download the merged file. No Preview, no Pages, no installed software — and it works the same way on Apple Silicon and Intel Macs.
Can I merge PDFs on an iPhone or iPad?
Yes. The interface is fully touch-friendly. Pick PDFs from the Files app or AirDrop them in, reorder by dragging, and tap merge — the result saves directly to Files.
Why is my merged PDF a different size than the originals?
Filoraio doesn't recompress images or strip fonts during the merge — the output is the sum of the inputs. If you need a smaller file, run our Compress PDF tool on the result. Never trust a merger that silently shrinks your file: it's almost certainly degrading image quality.
Does merging PDFs lose quality?
No. Filoraio copies pages verbatim — fonts, images, vector graphics, and form fields are preserved exactly as they appear in the originals. There's no re-rendering, re-encoding, or quality loss.
What do I do if the merge button stays disabled?
You need at least two PDF files. If you've added just one, the button waits until a second file is added. If your files don't show in the list at all, they may not be valid PDFs — most often they're .pages, .docx, or images saved with a .pdf extension.
Can I undo a merge or get my original files back?
Your original files are untouched — the merge produces a new PDF, it doesn't modify the inputs. To start over with different ordering, just refresh the page or click "Clear all" in the file list.
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Keep going
What people do next
Tools picked because they pair naturally with the one above — the next step in a typical PDF workflow.