Merge PDF Files Into One Document

Yes, completely free. Our Merge PDF tool has no hidden costs, no watermarks, and no registration requirement. You can process as many files as you need, each up to 100MB, at no charge. We believe professional PDF tools should be accessible to everyone — students, freelancers, and businesses alike.

Your files are fully protected. All uploads and downloads use 256-bit SSL/TLS encryption during transfer. Processing happens on our isolated Hetzner server infrastructure in Germany — your file is never shared, analysed for commercial purposes, or stored longer than necessary. Every uploaded and processed file is automatically and permanently deleted within 24 hours of processing.

Supported file types: This tool accepts PDF files up to 100MB each. Up to 20 PDFs in a single merge; the merged document itself has no page limit.

Yes, and picking several files at once is the only part worth knowing about. On a phone the file picker opens your Files or Drive app rather than a desktop folder, so tap and hold to multi-select before confirming. Once the files are up, the order list reorders by press-and-drag, exactly as it does with a mouse.

Up to 20 files per merge, no page limit. Each individual file can be up to 100MB. There is no cap on the total number of pages in the merged output — you can combine a 500-page document with a 300-page document and the result will be a single 800-page PDF. Drag the uploaded files into your preferred order before clicking Merge to control the final page sequence precisely.

Each source document arrives with its own embedded font subsets, colour handling and page geometry, and merging keeps all of it. Combine a Word export, a scanned invoice and a slide handout and you get one file in which each section still renders exactly as its originator intended. Nothing is re-rendered or normalised on the way through. The practical consequence is that the merged PDF carries several font subsets where the originals each carried one, which is the usual reason a combined file is slightly larger than the sum of its parts.

The 100 MB ceiling applies to every file you add, and the tool accepts up to 20 files in a single pass — so a batch can be rejected on file count while every member of it is comfortably within the size limit. Count the files in the upload list before processing. If you genuinely need to combine more than 20, merge them in two rounds and then merge the two results, which produces an identical document to a single 40-file pass.

Merging is a whole-document operation: files go in end to end, in the order shown on screen. The moment you need pages from one file to land between pages of another — an appendix dropped into the middle of a report, or two documents interleaved — merging cannot express that. Use Organize PDF, which accepts several documents at once and lets you place individual pages anywhere in the final sequence.

Form fields survive the merge, but PDF field names are document-wide identifiers rather than per-page ones. If two source files each contain a field called signature or date, the merged document ends up with a name collision, and typing in one box can populate the other. Flatten the forms in each source before merging if the fields are already filled in, or rename them if they still need to be completed after combining.