Merge PDF
Combine multiple PDF files into one document, reorder pages, and download — free, fast, and 100% private. Your PDFs never leave your browser.
Drag and drop PDF files here
Add two or more PDFs — up to 100 MB each
Merging happens entirely in your browser — your PDFs are never uploaded.
Combine PDFs Without Uploading Anything
Merging PDFs is one of the most common document tasks — stitching together signed contract pages, combining scanned receipts into a single expense report, or assembling chapters into one manuscript. Most online mergers ask you to upload your files to their servers, which is a privacy risk for anything sensitive. This Merge PDF tool works differently: every file you add is processed locally in your browser, so your documents never touch a remote server.
Under the hood it uses pdf-lib, a well-tested open-source PDF engine that copies each
page from your source files into a single new document. The result is a clean, standards-compliant
PDF that opens correctly in Acrobat, Preview, Chrome, and every other reader.
How to Merge PDF Files
The process takes seconds and requires no sign-up:
- Add your files — drag and drop multiple PDFs onto the drop zone, or click Choose Files to pick them. You can add more at any time.
- Set the order — drag-free reordering with up and down arrows lets you arrange the documents in the exact sequence you want.
- Remove mistakes — click the X next to any file to drop it from the merge without starting over.
- Merge and download — once you have two or more files, click Merge and the combined
merged.pdfdownloads instantly.
Privacy and Reliability
Because the merge runs client-side, there are no upload limits driven by a server, no queue, and no retention of your data. Nothing is logged or stored. This makes the tool ideal for legal documents, medical records, financial statements, and any file you would rather not hand to a third party. If a file fails to merge, it is almost always because it is encrypted or damaged — remove it and the rest will combine cleanly.
Frequently Asked Questions
Are my PDF files uploaded to a server when I merge them?↓
No. This tool merges your PDFs entirely inside your browser using the open-source pdf-lib library. Your files are read from your device, combined locally, and the merged PDF is generated in memory — nothing is ever sent over the network. You can even disconnect from the internet after the page loads and the merge will still work, which makes it safe for confidential contracts, invoices, and personal documents.
How do I change the order of the PDFs before merging?↓
After adding your files, each PDF appears in a numbered list. Use the up and down arrows next to a file to move it earlier or later in the sequence. The final merged document follows the order shown in the list from top to bottom, so arrange them exactly how you want before clicking Merge.
Is there a limit on how many PDFs or how large they can be?↓
You can merge as many PDFs as you like — there is no account or paywall. Because everything runs in your browser, the practical limit is your device’s available memory. Each individual file should be under 100 MB; very large or scan-heavy PDFs may take a few seconds and use more RAM than small text documents.
Why won’t one of my PDFs merge?↓
The most common cause is a password-protected or encrypted PDF — these must have their protection removed before they can be combined. Corrupt files or files that are not actually valid PDFs (despite a .pdf extension) will also fail. If you see an error, remove the problem file from the list and try merging the rest.