Merge PDF Files Free - Combine PDFs in Your Browser, No Upload

What it does: combines PDF files, and JPG or PNG images, into one PDF right in the browser. Drop the files, put them in order, type page ranges like 1-3, 5, 8- for the files you only need part of, and press Merge PDF. The Pages view shows a thumbnail of every page, so single pages can be dragged to a new place, turned, or removed before merging. Pages are copied as they are, not printed again: text stays selectable and searchable, and links, fonts, and image quality do not change. Each file gets a bookmark with its own bookmarks inside, form fields stay fillable, and password-protected PDFs open when you type the password. Nothing is uploaded: the files are read and merged on the visitor's device, and the page keeps working offline once it has loaded.

Who it is for: anyone who needs to put PDFs together: office workers joining reports, contracts, and receipts, students merging lecture notes and scans, freelancers sending one file instead of five. It is also for site owners who want a private PDF merger on their own domain, with no server to run and no per-task limits.

What you get: use it free in the live preview above, or take the whole tool: a one-page site for any static host (no build step, no server, no database, no API keys), the PDF engine as separate JavaScript modules you can reuse in your own code (opening encrypted PDFs, assembling pages, bookmarks, page ranges, ZIP), one config file for the name, colours, and size limits, HTML documentation on hosting, settings, embedding with an iframe, and the engine API, and Node.js tests with sample files, including PDFs encrypted with RC4 and AES.

What you do: upload the merge-pdf folder to your host (Cloudflare Pages, Netlify, Vercel, GitHub Pages, or your own server), open the page, and merge. Change the name, colour, and limits in js/config.js.

Features

• Files never leave the device: reading, decrypting, and merging all happen in the browser, in a background worker
• Drag and drop, file picker, or paste, many files at once, JPG and PNG images become pages (own size, A4, or US Letter, phone photos stand upright)
• Reorder files by dragging (mouse or touch), with arrow buttons, or sort by name A to Z / Z to A
• Page ranges per file: 1-3, 5, 8-, 7-2 backwards, last, odd, even, with a clear message for a wrong range
• Pages view: thumbnails of every page, select, drag, rotate, and remove pages, also with the keyboard
• Lossless: pages are copied, so text, fonts, links, and image quality stay exactly as they were
• Bookmarks: one per file with each file's own bookmarks under it, one per file, only the files' own, or none
• Password-protected PDFs open with their password (RC4 40/128-bit, AES-128, AES-256), files with only editing restrictions open without one
• Form fields keep working, fields with the same name in different files are renamed so their values stay apart
• Links between pages and named destinations keep working
• Optional blank page after files with an odd page count, for double-sided printing
• Clear messages for empty, damaged, or non-PDF files, the other files still merge
• Large files: 3 files of 96 MB plus a 1,500-page file merged in under 2 seconds in Chrome, with the page staying responsive
• Editable output name, no watermark, no sign-up, no task limits
• Works with the keyboard, on phones, in Chrome, Firefox, and Safari, and inside an iframe (it reports its height)

Screenshots