PDF Merger

PDF Merger copies every page from the selected files into one new PDF. The output follows the file-card order on screen. The default download name is merged.pdf unless you type another name.

• You have two or more complete PDFs that should become one document.
• You can arrange files, not individual pages, into the order you need.

• Join a cover PDF and a body PDF in card order.
• Stack several invoices into one file named something other than merged.pdf.
• Keep each source file’s internal page sequence while concatenating the files.

Each file is inspected locally: empty files are rejected, the first five bytes must be %PDF-, and pdf-lib must report at least one page. Merge creates a new PDFDocument, loads each source, copyPages for all page indices, then save().

Files

Minimum 2, maximum 25 PDFs.

Per file

50 MB.

Batch

200 MB combined.

Output

One PDF, default name merged.pdf.

1. Add at least two valid PDFs within the count and size limits.
2. Review the file cards and any validation messages.
3. Reorder with drag-and-drop or arrows.
4. Optionally rename the download.
5. Click Merge PDFs.
6. Open the result and check the page sequence.

Pages are copied, not redrawn as images, so text may remain selectable. Source page dimensions and orientations are left as copied. Document-level bookmarks and named destinations are not rebuilt in the new file. A newly written PDF typically invalidates certificate signatures.

• Encrypted PDFs are rejected at inspect time.
• Corrupt or non-PDF files fail.
• Large batches can slow or fail in the browser; reduce count or bytes.

Merge runs in the browser with pdf-lib. Files are not uploaded to a merge API. Identified analytics may include file counts, page counts, and byte totals, not filenames or document text.

• PDF Page Extractor builds one PDF from selected pages of a single file.
• PDF Splitter writes one or more PDFs into a ZIP, including one-file-per-page mode.
• Image to PDF / JPG to PDF create PDFs from images, not from existing PDFs.

• Confirm file order became page order.
• Check mixed page sizes and rotation.
• Recheck links, forms, and bookmarks if you rely on them.
• Keep the source PDFs; merge writes a new file and typically invalidates certificate signatures.