The ToolMint PDF Merger combines multiple PDF files into one downloadable PDF directly in your browser. You can upload PDFs, add more files later, reorder them, remove the ones you do not need and download a single merged document without creating an account or sending the files to ToolMint servers.
This tool is built for everyday document assembly: joining reports, combining scanned receipts, bundling signed forms, putting appendices after a proposal or turning several exported PDFs into one shareable file. It is not a PDF editor, compressor or repair tool. Its job is to preserve the pages from each source PDF and append them in the order you choose.
What a PDF merger does
A PDF merger takes complete PDF files and writes their pages into a new PDF. If you add three files, the merged output contains every page from the first file, then every page from the second file, then every page from the third file. Page dimensions and orientation are preserved because the tool copies PDF pages instead of converting them into screenshots.
That makes merging different from converting images to PDF. If your starting files are JPG, PNG or WebP images, use the Image to PDF Converter. If your files are already PDFs and you only need one combined document, use this PDF Merger.
How to merge PDF files
Start by adding at least two PDF files. You can drag files onto the upload area or use the Add PDFs button to open your device picker. The selected-file list shows each file name, file size and position number.
Before merging, review the order carefully. Use drag and drop on desktop, or use the move up and move down buttons on any device. These buttons are useful on mobile because precise dragging can be awkward on small screens. Remove any file that should not appear in the final document.
When the order is correct, click Merge PDFs. ToolMint loads each selected file locally, copies all pages into a new PDF in the displayed order and creates a browser Blob for download. After processing finishes, click Download Merged PDF to save merged-document.pdf.
Why file order matters
The merger does not guess which document should come first. The list order is the final page order. If a cover letter belongs before a contract, place the cover letter first. If an appendix belongs at the end, move it after the main file. For repeated workflows, such as monthly reporting, use a consistent order so recipients know where to find each section.
Order is especially important when combining scans. A scanner app may export separate PDFs for front pages, back pages, receipts or forms. If those files are not arranged before merging, the final PDF may be technically valid but confusing to read.
Privacy and local processing
PDF files are processed locally in the browser. The tool uses the browser File API to read selected files and a browser-compatible PDF library to copy pages into a new document. ToolMint does not upload your PDFs, store document contents or send filenames to analytics.
Files remain in the current browser tab while you work. They disappear from the tool when you refresh the page, close the tab or click Reset. This is useful for routine document assembly, but it is not a guarantee of absolute confidentiality. Avoid adding private or regulated documents on shared devices, managed browsers or untrusted computers.
Common mistakes
The most common mistake is trying to merge a single file. A merger needs at least two PDFs; if you only have one PDF, there is nothing to combine.
Another mistake is adding a file that has a .pdf extension but is not really a PDF. The tool checks for an obvious PDF header before accepting files, but some damaged files may only fail during processing.
Locked PDFs are another frequent cause of failure. Password-protected or encrypted PDFs usually need to be unlocked in another PDF editor before a browser-side merger can copy their pages. If a PDF fails, try opening it locally, exporting an unlocked copy and adding that copy again.
Large batches can also cause problems. ToolMint uses practical browser-side safeguards: up to 20 PDFs and about 100 MB of combined input size. These limits help avoid crashes on phones and lower-memory devices, but they are not universal PDF limits.
Limitations
The PDF Merger does not split files, delete individual pages inside a PDF, compress output, add page numbers, run OCR, edit text or repair corrupted documents. It combines whole PDFs in the selected order.
Advanced PDF features can vary after merging. Most ordinary pages, dimensions and orientations are preserved, but interactive forms, scripts, signatures, annotations or unusual embedded assets may behave differently depending on the source PDFs and browser-side library support.
If your goal is to reduce image-heavy PDFs before sharing, start with source images where possible and optimize them using the Image Compressor or Image Resizer before creating a PDF. If you need to verify a file after download, the Hash Generator can create a checksum for the merged output.
Related ToolMint tools
Use the Image to PDF Converter when your source files are JPG, PNG or WebP images rather than PDFs. Use the Image Compressor and Image Resizer before PDF creation when large images are making documents heavy. Use the Base64 Encoder only when a workflow specifically needs PDF bytes encoded as text, and use the Hash Generator to compare or archive file checksums.
Browse more quick utilities in the Utilities category. The FAQ section below this guide is generated from the ToolMint tool registry so visible FAQ answers and FAQ structured data stay synchronized.