Merge PDF
Join PDFs into one file. Everything happens in this tab.
Your files stay in this tab. There is no upload endpoint on this site.
Merging without handing over your documents
Most free PDF merge sites upload your file to a server, process it there, and promise to delete it later. For a holiday itinerary that is an acceptable trade. For a signed contract, a medical record, a bank statement or anything covered by a confidentiality agreement, it is a data transfer you probably did not intend to make and cannot verify.
This tool merges in the page itself using the pdf-lib library compiled to run in the browser. Your documents are read into memory, combined, and handed straight back as a download. Open your browser's Network tab and watch — there is no request carrying your file, because there is nowhere for it to go.
What is preserved
Every page from every input document is copied into the output in the order the files were added, retaining its original dimensions and orientation. Mixed page sizes are fine: an A4 report followed by a US Letter appendix keeps both formats rather than forcing everything to one size. Embedded fonts and images travel with their pages, so the merged document renders identically to the originals.
Interactive form fields, digital signatures and document-level annotations are not carried over. Merging invalidates a digital signature by definition — the signed byte range no longer exists — so a signed PDF should be merged only when the signature no longer needs to verify.
Encrypted files
A password-protected PDF cannot be read without its password and will be rejected with an error. Remove the protection in the application that created it, then merge the unprotected copy.
Common questions
Do my files get uploaded to a server?
No. Every tool on this site runs entirely in your browser using the Canvas and WebAssembly APIs. There is no upload endpoint in the page — you can confirm this yourself by opening your browser's Network tab while you convert a file. Nothing leaves the tab, which also means the tools keep working if you go offline after the page loads.
Is there a limit on file count or size?
No imposed limit. The constraint is available memory, since every document is held in RAM while merging. Desktop browsers handle hundreds of megabytes; a phone will struggle well before that.
Can I reorder or delete individual pages?
Not within this tool — it merges whole documents in the order they were added. Page-level editing needs a full PDF editor.
Will my digital signature survive the merge?
No. A digital signature covers an exact byte range in a specific file, and merging necessarily changes it. The signature will show as invalid in the merged document.