Combine multiple PDFs into one — drag, drop and reorder them, all client-side.
This tool runs entirely in your browser — no data is sent to our servers. If JavaScript is disabled, the fully interactive version will not run; enable JavaScript to compute results.
Merging PDFs is one of the most common document tasks. Bills, receipts, contracts and reports often arrive as multiple files when the recipient wants them as one. This tool combines them in the order you specify, all in your browser.
The merge preserves the original page contents, fonts and embedded objects. Page order in the final PDF matches the order in the file list — drag items up or down to rearrange before generating.
For very large PDFs (hundreds of pages each, or many files at once), browser memory becomes the constraint. For smaller, everyday merges (a few files of typical document size), the tool is instant.
The tool uses the open-source pdf-lib library, which is the same engine trusted by dozens of accounting, HR and legal SaaS products for programmatic PDF assembly. Because it runs in your browser via WebAssembly-compatible JavaScript, the files never leave your device — that matters when you are combining medical scans, ID copies or contracts that should not travel through a third-party server. Merged output uses the same PDF 1.7 structure the input files rely on, so page fidelity is preserved: text stays selectable, hyperlinks continue to resolve, form fields (where present) remain interactive, and any pre-existing digital signatures on individual pages are carried through untouched.
A common workflow this tool solves in one step: you receive a quotation as a two-page PDF, an amendment as a one-pager and an appendix as five scanned pages, and your finance system requires a single PDF for filing. Drop all three in, reorder, hit merge, and you have a single archive-ready file in seconds. For accountants combining monthly bank statements before an audit, for landlords consolidating multi-page lease documents before signing, and for anyone assembling a portfolio from separately-generated pages, the merge step is the last five seconds before the paperwork is done.
Roughly the sum of the input file sizes, with a small overhead. Embedded duplicate fonts get deduplicated automatically.
No. The merge uses pdf-lib in your browser. The files stay on your device.
Only if they have no password protection. Password-protected PDFs need to be decrypted first using the original password.
Convert the images to PDF first (use the Image to PDF tool), then merge them alongside the text PDFs. Mixing raw image files into the merge is not supported because the merge operates on PDF documents only, but the two-step workflow (image → PDF → merge) covers this use case in under a minute.
Yes for bookmarks that sit inside each input document. Because there is no way to know how you want them structured across the combined file, the tool concatenates each document's bookmark tree in order rather than trying to synthesise a new top-level index. Reorganise the bookmark tree in a full editor if the specific hierarchy matters.
The first document's metadata becomes the merged document's metadata by default. To change it, open the merged PDF in any editor and update the document properties — the rest of the file is untouched.
The Merge Multiple PDF Files lives alongside Image Compressor, Image Resize, Image to PDF on the Image & File page. That landing page collects every image & file tool Dailiyo publishes, plus the editorial notes on formula sources, review cadence and how each result should (and should not) be interpreted. If a related image & file calculation isn't yet in the collection and you'd like to see it, drop a line via the contact page — the editorial team reviews every request and prioritises tools that come up most often in reader questions.