Merge PDF files without uploading them
Combine two or more PDFs into a single document, in your browser, in a few seconds. It is free, there is no page limit and no watermark — and unlike every other online merger, your files never leave your device.
No sign-up. No upload. Nothing to install.
How to merge PDF files
- Open PDFLight. Go to the editor. There is nothing to install and no account to create.
- Drop your PDFs. Drag every file you want to combine onto the page. Each one opens in its own tab — they stay on your device the whole time.
- Put them in order. Drag the tabs left or right. The tab order is the merge order, so what you see is what you get.
- Merge. Open the Merge menu and choose "Merge all tabs". The documents are combined into one.
- Save. Click Save. The merged PDF is written straight to your disk.
Why merge in the browser rather than on a server
Every other free PDF tool works the same way: you upload your file, a server you know nothing about processes it, and you trust it to delete the copy afterwards. PDFLight does not. The entire editor is JavaScript running on your own machine, so your document is read into your browser's memory and never travels anywhere. There is no upload endpoint — not as a policy, but as a fact of how the application is built.
That matters most for exactly the documents people merge: contracts assembled from several signed pages, an invoice bundle for an accountant, scans of an ID, a mortgage file. These are the documents you would least like to hand to an unknown third party — and they are the ones online mergers are used for every day.
Working locally is also simply faster. There is no upload, no queue, no download: a 200-page merge is limited by your own machine, not by your connection.
Frequently asked questions
Is merging PDFs really free?
Yes. There is no file limit, no page limit, no watermark and no paid tier. PDFLight is funded by ads on its content pages, never inside the editor.
How many PDFs can I merge at once?
As many as your browser can hold in memory — in practice, dozens. Each opens in its own tab and the tab order sets the merge order.
Are my files uploaded anywhere?
No. The merge happens entirely in your browser using JavaScript. Your documents are never transmitted over the network.
Can I reorder the pages after merging?
Yes. Once merged, you can drag pages into any order, rotate them, duplicate them or delete them, then save.
Does it work offline?
Yes. Install PDFLight as an app and it keeps merging with no connection at all — which is only possible precisely because nothing is uploaded.