DocLab

Merge PDF

Merge PDF lets you combine several PDF files into one document, in whatever order you set, without uploading anything. Add your files, arrange them top to bottom, and download the joined PDF — the whole merge runs locally in your browser, so your documents never leave your device.

Drop PDFs here

or

Add two or more PDFs — they're combined in the order shown below.

    100% private. Your PDFs are combined right here in your browser — they are never uploaded to a server.

    Need OCR, redaction, or to edit text? Get the free DocLab desktop app →

    Merge PDF — how it works

    1. Add your PDFs. Drop two or more PDF files onto the page or use Choose PDF files; each one is read in your browser and shown with its page count.
    2. Set the order. Use the up and down arrows to arrange the files top to bottom — that's the exact order their pages appear in the final document — and remove any you don't want.
    3. Merge and download. Click Merge & download and the combined file saves to your device, ready to open or share.

    Your files never leave your browser

    Merging happens entirely inside your own browser tab — there is no upload step and no server that ever receives your PDFs. When you add files, they're read into memory locally, combined by code running on your machine, and handed straight back as a download; nothing is stored or transmitted. A strict Content Security Policy blocks the page from sending your documents anywhere, and because the work is local, the tool keeps running even after you go offline once the page has loaded. The whole site is open source, so anyone can read exactly how it handles your files. For confidential contracts, statements, or records, that means you can merge without uploading and without trusting a third party with your data. Read the privacy policy →

    Why use DocLab

    Frequently asked questions

    Are my files uploaded when I merge them?

    No. The merge runs entirely in your browser using a local Web Worker, so your PDFs are never sent to a server or stored anywhere — they stay on your device the whole time.

    Is it free, and do I need an account?

    Yes, it's completely free with no account, sign-up, email, or watermark. Just open the page, add your PDFs, and download the merged file.

    Is there a limit on how many files or pages I can merge?

    There are no built-in limits on file count, file size, or pages. Very large merges are bounded only by your device's available memory, since all the work happens locally.

    Does it work offline and on Mac or mobile?

    Yes. It runs in any modern browser on Windows, Mac, Linux, ChromeOS, and phones or tablets, and once the page has loaded it continues to work without an internet connection.

    Why won't one of my PDFs merge?

    Password-protected or damaged PDFs can't be read and are flagged in the list so they're skipped. Unlock or repair the file first — the free DocLab desktop app handles encrypted and complex documents.

    Related PDF tools

    More than merge pdf?

    The full DocLab editor reorders, rotates, annotates, signs, numbers, watermarks, and converts — all in one place, still 100% in your browser.

    Get the free desktop app →