Is there a limit on how many PDFs I can merge?

There is no fixed limit. The practical ceiling is your device's memory, since the merge happens on your own machine — a few hundred pages is comfortable on a typical laptop or phone. If a very large batch feels slow, merge it in two passes.

Will merging reduce the quality of my pages?

No. Pages are copied across intact, with their original resolution, fonts and embedded images. Merging is a structural operation, so nothing is re-encoded or recompressed.

Can I merge PDFs of different page sizes?

Yes. Each page keeps its own dimensions, so an A4 report and an A3 drawing can sit in the same file. If you need them all one size, use the Organize or Scale tools afterwards.

Are my documents uploaded to your server?

No. Because it runs in your browser, the file never leaves your device. You can confirm it by opening your browser's developer tools and watching the network tab while you merge — no request carries your file.

Merge PDF

Combine multiple PDFs into a single document, in the order you choose.

Processed locally in your browser — files never leave your device

What Merge PDF does

Combining PDFs is the most common reason people go looking for a PDF tool: a scanned contract arrives in three parts, or a report needs its appendices attached. Add your files below, drag them into the order you want, and download a single document. Bookmarks and page sizes from each source are preserved as-is.

How it works

A PDF is a container of self-describing objects — pages, fonts, images — rather than a flat stream of content. Merging therefore does not mean re-printing anything: the tool opens each source document, copies its page objects (together with the fonts and images those pages reference) into a new document in the order you arranged, and writes the result out.

Because pages are copied rather than re-rendered, nothing is recompressed and nothing is redrawn. The output is byte-for-byte faithful to each source page, which is why a merged file looks identical to the originals in any reader and prints exactly the same way.

When to use it

A document was scanned or exported in several parts and needs to be sent as one file.
A report, proposal or application needs its appendices, cover letter or supporting exhibits attached in a fixed order.
Several invoices or receipts for the same claim need to be submitted as a single attachment.
A form portal or email system accepts only one file, and you have three.

Advantages and limitations

Advantages

No upload: merging happens on your device, so a 200 MB batch starts instantly instead of crawling up a connection.
No watermark, sign-up or page-count cap — the output is your document and nothing else.
Original quality is preserved exactly, because pages are copied rather than re-encoded.
Order is fully under your control: drag files into any sequence before merging.
Works offline once the page has loaded, since no server is involved.

Limitations

Encrypted (password-protected) sources must be unlocked first — use the Protect / Unlock tool, then merge.
Interactive form fields with the same name in two source files can collide, since PDF requires field names to be unique within a document.
Very large batches are limited by your device's memory rather than by any server quota; if a huge merge feels slow, do it in two passes.
The tool merges whole files — to combine selected pages from different documents, split those pages out first.

Security and privacy

This tool runs entirely on your own device. The file you choose is read into your browser's memory, processed there by JavaScript, and returned to you as a download — no part of it is transmitted to our servers or anyone else's. When you close or reload the page, the browser discards that memory. We never see your document, cannot log it, and have nothing to delete afterwards. You can verify this yourself: open your browser's developer tools, switch to the Network tab, and process a file — you will see no request carrying your document.

The full detail of how this site handles data is in our Privacy Policy.

Supported files

Input: any number of standard PDF files (.pdf), including PDFs produced by scanners, office suites and export functions, of any page size or orientation. Encrypted PDFs must be unlocked first. Output: a single .pdf containing every page of every input in your chosen order.

How to use Merge PDF, step by step

Click the upload area or drag your PDF files onto it. You can add them all at once or a few at a time.
Drag the files in the list into the order you want them to appear in the final document.
Remove any file you added by mistake using its delete button.
Click Merge. The combined document is assembled on your device in a few seconds.
Download the merged PDF and open it to confirm the page order is what you expected.

Frequently asked questions

Is there a limit on how many PDFs I can merge?: There is no fixed limit. The practical ceiling is your device's memory, since the merge happens on your own machine — a few hundred pages is comfortable on a typical laptop or phone. If a very large batch feels slow, merge it in two passes.
Will merging reduce the quality of my pages?: No. Pages are copied across intact, with their original resolution, fonts and embedded images. Merging is a structural operation, so nothing is re-encoded or recompressed.
Can I merge PDFs of different page sizes?: Yes. Each page keeps its own dimensions, so an A4 report and an A3 drawing can sit in the same file. If you need them all one size, use the Organize or Scale tools afterwards.
Are my documents uploaded to your server?: No. Because it runs in your browser, the file never leaves your device. You can confirm it by opening your browser's developer tools and watching the network tab while you merge — no request carries your file.