Are my PDF files uploaded to a server?

No, all PDF merging happens locally in your browser. Your files never leave your device, ensuring complete privacy and security.

Is there a limit on the number of files I can merge?

There is no fixed limit on the number of files. You can merge as many PDFs as your browser memory allows, which is typically more than enough for any practical use case.

Does merging affect the quality of my PDFs?

No, the merging process preserves the original quality of all pages. Text, images, fonts, and formatting remain exactly as they were in the source files.

Can I reorder pages before merging?

Yes, you can drag and drop files to reorder them before merging. The pages will appear in the merged document in the order you arrange the files.

Do bookmarks survive merging?

No. The merged file is built by copying pages into a new document, and the outline tree that holds bookmarks belongs to the document rather than to any page, so it is not carried over. Rebuild the bookmarks in a PDF editor after merging if you need them.

Do hyperlinks still work in the merged PDF?

Yes. Link annotations are attached to individual pages, so they travel with the page and remain clickable in the merged file. Links that pointed to a page inside the same document may land in the wrong place, because page numbering changes when files are joined.

What happens to fillable form fields?

They lose their interactivity. Form fields are registered in a document-level AcroForm dictionary that is not copied, so the field boxes are flattened out of the merged file and can no longer be typed into. Fill the form first, then merge.

Is the document title and author carried over?

No. Metadata such as title, author, subject and keywords lives on the source document and is not copied to the merged file, which starts with empty metadata. Set it again in a PDF editor if it matters for your document management system.

Can I merge password-protected PDFs?

No. An encrypted PDF fails to load and the tool reports an error, because the parser refuses documents that carry an encryption dictionary. Remove the password in the application that created the file, then merge the unprotected copy.

What order do the pages come out in?

Pages appear in the order the files are listed, and within each file the original page order is kept. Drag the files into the order you want before merging - there is no page-level sorting at this stage.

Can I merge PDFs with different page sizes?

Yes. Page size is a property of each page, so an A4 document and a US Letter document merge without either being resized or cropped. The result is a single file whose pages are not all the same dimensions, which is normal and prints correctly.

How big will the merged file be?

Roughly the sum of the inputs. Nothing is re-encoded or downsampled, so images and fonts carry over at their original quality and the total is close to the combined size, minus a little from shared object compression.

Why is the merged file slightly smaller than the sum of its parts?

Because the new document is written with cross-reference streams and object streams, which pack the PDF structure more tightly than older writers did. The page content itself is untouched - the saving comes from the file scaffolding, not from your images.

Can I merge scanned PDFs?

Yes, and the scans are copied without being re-encoded, so image quality is identical to the source. Scanned pages are large, so a merge of several long scanned documents can use a lot of browser memory.

Is there a file size limit?

There is no fixed limit, because nothing is uploaded. The practical ceiling is your browser tab's memory: every source file is held in memory alongside the output, so very large merges are the ones that fail, and they fail by running out of memory rather than by being rejected.

Does merging work offline?

Yes. Once the page has loaded, merging runs entirely in the browser and needs no network connection. You can disconnect and keep working.

Can I merge a PDF with a Word document or an image?

No. This tool takes PDF input only. Export the Word file to PDF, or convert the image to PDF first, then merge the resulting files.

Why did my merge fail with no error?

The most common cause is a damaged or non-standard PDF that the parser cannot read - some files produced by older scanners and by certain print drivers are not valid PDF even though a viewer will display them. Opening and re-saving the file in a PDF viewer usually repairs it.

There is nothing to undo: the tool never modifies your source files, it writes a new document and offers it as a download. Your originals are untouched on disk, and you can discard the merged file and start again.

Merge PDF

Combine multiple PDF files into a single document with drag-and-drop reordering

Merge PDF Files

Drop PDF files here or click to browseSelect multiple PDF files to merge

Category:pdf

Mode:Offline

Version:1.0.0

Access:Free

What is Merge PDF?

Merge PDF interface on Toolz.dev - Combine multiple PDF files into a single document with drag-and-drop reordering

Merge PDF is a free online tool that combines multiple PDF files into a single document. Whether you need to merge reports, combine scanned pages, or join related documents, this tool makes it easy with a simple drag-and-drop interface.

The tool lets you add multiple PDF files and reorder them by dragging and dropping before merging. This gives you full control over the final page order. The merged output preserves the formatting, page dimensions and image quality of each source document.

All PDF processing happens entirely in your browser using client-side technology. Your files are never uploaded to any server, making this the most private way to merge PDFs online. There are no file size limits, no watermarks, and no registration required.

Two things are worth knowing before you merge. Pages are copied object for object, so text stays selectable and images keep their original resolution, but the document outline does not come across: if either input carried bookmarks, the merged file will not. Interactive form fields behave the same way, so a filled AcroForm is safer flattened before merging. Memory is the other constraint. Every file is held in the tab while it works, so a few hundred megabytes of scans can exhaust a browser that would handle the same job comfortably on the desktop. If a file refuses to load at all, it is almost always password-protected, and the password has to come off in a reader first. Order comes from the list on screen rather than from filenames, so arrange the files before you download.

How to use Merge PDF?

Add PDF files

Drag and drop multiple PDF files onto the tool or click to browse and select them from your device. Add as many files as you need.

Reorder files

Drag and drop the files to arrange them in the order you want them to appear in the merged document.

Merge the PDFs

Click the merge button to combine all selected files into a single PDF document. The process takes just seconds.

Download the result

Download the merged PDF file to your device. The combined document is ready to share, print, or archive.

Key Features

Keeps Text Selectable

Pages are copied as they are rather than rasterised, so text, links and fonts in the merged file work exactly as they did in the originals

Drag-and-Drop Reordering

Easily rearrange PDF files by dragging and dropping to control the order of pages in the merged document

Preserves Quality

The merged PDF maintains the original quality, formatting, and metadata of all source documents

No File Limits

Merge as many PDF files as you need with no restrictions on file size or number of documents

Frequently Asked Questions

Yes, Merge PDF is completely free with no watermarks and no registration required.

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