PDF Merger

What a PDF merger does

A PDF merger combines two or more separate PDF files into a single document, in whatever order you choose. Instead of sending a recipient five separate attachments — a cover letter, a resume, and three reference letters, for example — you can merge them into one PDF that opens as a single, properly ordered document from start to finish.

Nonkera's merger is being built to run entirely in your browser using WebAssembly, meaning the actual merging happens on your device rather than on a remote server. Your files stay local throughout the process instead of being uploaded, processed remotely, and downloaded back.

Why local, browser-based merging matters

Most free PDF tools online require you to upload your files to a third-party server before they can combine them — which means your documents, however sensitive, pass through infrastructure you don't control and often can't verify was deleted afterward. For contracts, tax documents, medical records, or anything else you'd rather not hand to an unfamiliar server, processing everything locally in your own browser closes that gap entirely.

It's also just faster for typical documents, since there's no upload or download wait — the merge happens as soon as you click the button.

Common use cases

Job seekers combine a resume, cover letter, and portfolio into one application PDF. Freelancers and small businesses merge an invoice with supporting receipts before sending it to a client. Students combine scanned homework pages or research excerpts into a single submission. Real estate and legal professionals merge multi-part contracts, disclosures, and signature pages into one file for easier review and e-signing.

Tips for merging PDFs

Before merging, double-check the page orientation and size of each source file — mixing portrait and landscape pages, or very different page sizes, can make the combined document awkward to read even though the merge itself works fine. Name your files in the order you want them to appear beforehand (like 01-cover-letter.pdf, 02-resume.pdf) so reordering during the merge is quicker, and always open the final merged file to confirm the page order and that nothing was accidentally duplicated before sending it on.

How browser-based merging is possible

Merging PDFs entirely in a browser tab is possible thanks to WebAssembly, a technology that lets code originally written in languages like C++ or Rust run at near-native speed directly inside the browser, without needing a server to do the heavy lifting. The PDF-manipulation logic runs on your device using your own computer's processing power, which is what allows a tool like this to skip the traditional upload-process-download cycle entirely — there's simply nothing to upload in the first place. This is the same general approach Nonkera uses across its document and image tools, prioritizing on-device processing wherever the browser is capable of it, and it's also why performance depends more on your own device's processing power than on anyone's server load or internet connection speed — a slow connection won't slow down the merge itself, and there's no queue to wait in even if a lot of other people happen to be using the site at the same time.