PDF Studio

No. Two JavaScript libraries do the work inside your browser: PDF.js draws the page previews, and pdf-lib assembles the finished document. Both are served from this site, so your files are read from disk into browser memory and written back out as a download. You can verify it by disconnecting from the internet after the page loads — the tool still works.

Yes, that is the point of the page grid. Once your files are loaded, every page is an independent thumbnail regardless of which document it came from, so you can interleave chapters, move a signature page to the end, or pull one page from each of five files into a new order.

Hover a page thumbnail (or just tap it on a phone) to reveal its controls. The rotate button turns that page 90° clockwise each press, duplicate inserts a copy directly after it, and the bin removes it. Nothing is applied to your original file — the changes are written only into the new PDF you export.

The preview and the export are separate steps. A page can fail to draw — an unusual font, a damaged object, an image format your browser cannot decode — and still copy into the finished PDF perfectly well, because pdf-lib moves the page data across without re-rendering it. The thumbnail is only a picture of the page, not the page itself.

There is no fixed limit. Previews are drawn only as you scroll to them, so a long document stays responsive, but every source file is held in memory while you work. A few hundred pages is comfortable on a desktop; a phone has far less headroom and may struggle with very large scanned documents.

We impose none. The practical limit is your device memory, because every document must be held in RAM while merging. Merging a few hundred megabytes is fine on a desktop; mobile devices have less headroom.

Encrypted PDFs cannot be read without the password, so they must be unlocked first. If you can open the document in your PDF reader, print it to a new PDF and merge that copy instead.

No. Pages are copied at full fidelity, preserving the original text, vector graphics and embedded images. Nothing is rasterised or re-compressed, so the output is visually identical to the inputs.

Page content, images and most annotations carry over. Document-level structures such as outlines and interactive form fields may be dropped or flattened, which is a known limitation of page-level copying.

Yes. After adding your files, use the move up and move down controls on each row. The final PDF follows the list order exactly, top to bottom.

Yes. There is no account, no trial, no watermark and no paid tier gating the output. Because processing happens on your device, serving the tool costs us almost nothing.