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Merge PDF

Combine multiple PDF files and images into one PDF, in any order and with only the pages you need. Free, and your files never leave your device.

Files are processed on your device and never uploaded to a server.

or drop them here

PDF, JPG, PNG, HEIC and other images. No limit on files or size.

How it works

A PDF merger combines several PDF files, or PDFs and images, into one document. This one runs in your browser: it copies the original pages with the open-source pdf-lib library, so text stays selectable, nothing is re-compressed and nothing is uploaded.

  1. Add your files

    Choose or drop PDFs and images. A locked PDF asks for its password, which is checked on this device.

  2. Set the order and pages

    Drag a file, use the arrows or sort by name. Type pages such as 1-3, 5 or pick them from thumbnails.

  3. Merge and download

    The new PDF is built in this tab. Download it, then split, compress or rotate it if you need to.

Where your files go

Nowhere. The page loads its code from airusk.com once (pdf.js to read and preview PDFs, pdf-lib to build the new one), then works on your files in this browser tab. No file, page or password is sent to a server, and closing the tab clears everything. To check, open your browser's developer tools, choose the Network tab and merge a few files: no upload appears.

What is kept and what changes

  • PDF pages are copied as they are. Text, fonts, vector graphics and images keep their quality, and rotated pages stay rotated.
  • JPG and PNG images are placed without re-compression, turned upright when a phone saved them sideways. HEIC, WebP and other formats are converted once to high-quality JPG or lossless PNG.
  • Locked PDFs are opened with the password you enter, and the merged file has no password.
  • Links to websites keep working. Bookmarks, fillable form fields and digital signatures of the source files are not carried over; use the bookmark option to add one bookmark per file instead.
  • Damaged or unusually built PDFs that pdf-lib cannot rebuild can still be added as images of their pages. They look the same, but their text can no longer be selected or searched, so the tool asks first.

No limits, except your device

There is no cap on the number of files, pages or megabytes, and no watermark. Very large jobs are bounded by the memory of your device: on a phone, merge files of several hundred megabytes in smaller batches.

Frequently asked questions

How do I merge PDF files for free online?

Choose or drop two or more PDF files above, set the order by dragging the handles, using the arrow buttons or sorting by name, and click Merge. Then click Download PDF to save the combined file. It is free, with no sign-up, no watermark and no limit on the number of files.

Is it safe to merge PDFs online without uploading them to a server?

Yes. This tool merges the files inside your browser tab and never uploads them, so your documents never leave your device. That makes it suitable for contracts, medical forms and other private files. You can confirm it in your browser's Network tab: no request carries your files.

Can I change the order of PDFs before merging them?

Yes. Files are listed in the order you chose them. Drag a file by its handle, use its up and down arrow buttons, or sort the list by name. The merged PDF follows exactly the order shown in the list.

How many PDF files can I merge at once?

There is no fixed limit on the number of files, pages or total size. The only limit is your device's memory: dozens of typical documents merge in seconds, while very large or image-heavy PDFs need more memory, especially on phones.

Does merging PDFs reduce the quality or resolution of the pages?

No. The tool uses pdf-lib, an open-source JavaScript library that copies PDF pages at the document structure level rather than re-rendering or re-compressing them, so text, vector graphics and image resolution are preserved. JPG and PNG images are placed without re-compression too.

Can I merge only some pages of a PDF?

Yes. Type the pages to keep in the Pages field next to a file, for example 1-3, 5 or 8- for page 8 to the end, or open the page thumbnails and click the pages you want. Typed pages are added in the order you type them, so 3, 1-2 puts page 3 first.

Can I merge password-protected PDFs or add images?

Yes. A locked PDF asks for its password, which is checked on this device, and the merged file has no password. JPG, PNG, HEIC, WebP, GIF, BMP and TIFF images can be added too. Each image becomes a page, sized like the first PDF (Letter if there is none), Letter, A4 or the image itself.