100% local · no uploads · free

Combine PDF Files

The accountant needs all twelve invoices in one file. The lawyer wants the contract, addendum, and signature pages merged. The student has scanned each chapter separately and needs a single thesis PDF. Every day, millions of people need to combine PDFs — and most end up uploading sensitive documents to a random website to do it.

KuroPDF merges your PDFs entirely in the browser. Drop them in, drag to reorder, click merge. The output is a proper, bookmarkable PDF with the correct page count and intact metadata. No server ever sees your contracts, tax returns, or medical records.

There is no file-count limit and no size cap. Merge two files or two hundred. A 500MB scan collection merges just as smoothly as a pair of one-page letters. The only constraint is your device memory.

The merge preserves everything: bookmarks, internal links, form fields, and annotations all carry through to the combined document. It is a true structural merge, not a "print to PDF" hack.

Open the Merge PDF tool →
  • Files never leave your device
  • No size limits
  • Free, no sign-up

How to combine pdf files

  1. 1
    Add your PDFs

    Drop multiple PDF files into the tool or click to browse. Add as many as you need — there is no limit.

  2. 2
    Arrange the order

    Drag files up and down to set the page order of the final document. Use A-Z sort for alphabetical/numeric ordering.

  3. 3
    Name your output

    Set a filename for the merged PDF. The default is "merged.pdf" but you can name it anything.

  4. 4
    Merge and download

    Click "Merge PDFs." The combined document downloads in seconds, ready to share or archive.

Frequently asked questions

Is there a limit on how many PDFs I can merge?

No limit. Merging runs locally on your device, so you can combine hundreds of files in a single session. The only real constraint is your device memory.

Can I reorder files before merging?

Yes — drag files up or down to set the exact page order. You can also sort alphabetically with one click if your files are named sequentially.

Are bookmarks and links preserved?

Yes. The merge engine preserves bookmarks, internal links, form fields, and annotations from every source file.

Does this work offline?

Yes. Once the page loads, all merging happens entirely offline using WebAssembly. No internet connection required.

Is it really free with no watermark?

Yes — completely free, no watermark, no sign-up, no daily limit. Use it as much as you need.

Is this safe for financial or legal documents?

Everything runs locally in your browser using WebAssembly. Because no data is uploaded to a cloud server, your files remain strictly private, and the entire process generates zero server carbon emissions, making it highly eco-friendly.

The real difference

Why KuroPDF exists

Every other PDF tool uploads your files to their servers. We think that is broken. Here is what we do differently - and what the alternatives actually cost you.

Nothing leaves your device

Files are processed in your browser using WebAssembly. Open DevTools → Network tab and verify: zero upload requests. Ever.

What competitors do instead:

Smallpdf, iLovePDF, and Adobe Acrobat all upload your files to their servers - your contracts, bank statements, and medical records pass through third-party infrastructure.

No file size limits, no daily caps

Process a 500-page PDF or batch-convert 200 photos. No cap, no throttle, no upgrade wall. Your device is the only limit.

What competitors do instead:

Smallpdf limits free users to 2 tasks per day. iLovePDF caps file sizes at 100MB. Adobe requires a $19.99/mo subscription for basic features.

Works completely offline

Install KuroPDF as a progressive web app. After the first visit, every tool works with zero internet - on a plane, in a bunker, wherever.

What competitors do instead:

Every cloud-based PDF tool stops working the moment your Wi-Fi drops. No connection = no work.

Real encryption, not security theatre

Password protection uses AES-256 encryption via a WebAssembly build of qpdf. The password never leaves your machine - there is no server to intercept it.

What competitors do instead:

When you 'protect' a PDF on Smallpdf or iLovePDF, your unencrypted file and password travel to their server, get processed, then get sent back. That is not security.

Free forever, no account needed

No login wall, no email harvesting, no 'continue with Google' popup. Open the site, use the tool, close the tab. Done.

What competitors do instead:

Adobe charges $239/yr. Smallpdf charges $108/yr. iLovePDF charges $84/yr. All require account creation to use basic tools.

Professional-grade codecs

MozJPEG for JPEG, OxiPNG for PNG, AVIF and WebP encoders - the same codecs used by Google and Mozilla. Not generic re-encoding.

What competitors do instead:

Most cloud tools use basic server-side encoders with less optimization control. You get worse compression at lower quality.

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