Merge PDF Files

What does this tool do?

Convixy PDF Merger lets you combine multiple PDF files into a single document directly from your browser — no software to install, no account to create, and no technical knowledge required. Simply select between two and five PDF files, upload them, and receive a single merged PDF within seconds. The page order in your merged file follows the order in which you selected the files, giving you full control over the final result. It works on all devices including Windows, macOS, Android and iOS without any setup. If you need to first convert a Word, Excel or PowerPoint file into PDF before merging, use our Word to PDF, Excel to PDF, or PowerPoint to PDF tools.

When do you actually need to merge PDFs?

There are many everyday situations where having one consolidated PDF is far more practical than managing separate files:

• Sending a job application — Combine your cover letter, CV, and reference letters into a single attachment instead of forcing a recruiter to open three separate files.
• Submitting a project or academic report — Merge individual chapter PDFs into one complete document for submission to a university portal or client system that expects a single file.
• Compiling invoices and receipts — Gather a month’s worth of invoices into one PDF for accounting reconciliation, expense claims, or tax preparation.
• Combining multi-page scanned documents — If you scanned a contract or form page by page, merge the individual scans into a single coherent, correctly ordered file.
• Preparing a client portfolio or proposal — Pull together multiple project PDFs into one presentation-ready document to share with potential clients or upload to a pitch platform.
• Organising legal documents for submission — Merge agreements, appendices, exhibits, and cover sheets into one filed document for court submission, notarisation, or archiving.
• Combining converted documents — Convert your Word, Excel, and PowerPoint files to PDF separately using our tools, then merge them all into one comprehensive document here.

Does merging PDFs affect quality or formatting?

No. The merge process used by this tool is entirely lossless — it joins the source files at the PDF document structure level without re-rendering, resampling, or recompressing any page content. Every page in the output file is bit-for-bit identical to the corresponding page in its source file. Images retain their original resolution and compression, text remains fully selectable and searchable, embedded fonts are preserved in their entirety, hyperlinks and annotations remain intact, and page dimensions stay exactly as they were in each source document. If you need to reduce the resulting file size, run it through our Compress PDF tool afterwards.

What is pdfunite and how does it work?

pdfunite is a command-line utility that is part of the Poppler PDF rendering library — a widely used, open-source PDF toolkit maintained by the freedesktop.org project. When you upload files to this tool, our server passes them to pdfunite in the order you selected them. pdfunite reads the cross-reference table and page tree of each source PDF, appends the page objects from each file into a new combined cross-reference table, and writes a new PDF output file containing all the pages in sequence. Because pdfunite operates at the object level rather than re-rendering the pages, the process is extremely fast and produces output that is structurally identical in quality to the source documents.

Will the merged PDF keep bookmarks from the original files?

This depends on how the source PDFs were created. pdfunite does not automatically merge the bookmark (outline) trees from multiple PDFs into a combined table of contents. If your source files have bookmarks, those will be preserved within each file’s section of the merged document, but they will not be consolidated into a single unified outline tree. For most everyday use — job applications, report submissions, invoice batches — this is not a concern. If you need a merged PDF with a unified, cross-document bookmark structure, you will need a dedicated PDF editing application such as Adobe Acrobat Pro.

What is the file size limit?

You can merge up to 5 PDF files per session. Each individual file must be under 10MB, and the combined total of all uploaded files must not exceed 15MB. These limits cover the vast majority of everyday documents. If your PDFs are large due to embedded high-resolution images, run them through our Compress PDF tool first to reduce the file sizes before merging. After merging, if the combined output is still large, you can compress the merged PDF too.

Does the order of files matter?

Yes, page order is fully determined by the order in which you select your files. The merged PDF contains the pages of the first file followed by the pages of the second file, and so on in selection order. To get the sequence you want, select or drag your files in the exact order you intend them to appear in the final document. Naming your files with a numerical prefix (e.g. 01-cover.pdf, 02-report.pdf, 03-appendix.pdf) before uploading is a reliable way to ensure your file picker presents them in the correct order for selection.

Can I merge more than 5 files?

The current limit is 5 files per session. If you need to merge more than 5 PDFs, use a two-pass approach: merge the first batch of up to 5 files into one PDF, download the result, then upload that merged PDF alongside your remaining files for a second merge. This method lets you combine any number of documents without restriction, and the output quality is identical to a single-pass merge since each pass operates at the structural level.

Why might a merge fail?

The most common reason a merge fails is that one of the uploaded files is password-protected or encrypted at the open-document level. Our tool cannot process PDFs that require a password to open — you will need to remove the password protection first using your original PDF software. Other causes include corrupted PDF files with invalid internal structure, and files saved in a non-standard or proprietary PDF variant that pdfunite cannot parse. PDFs with an owner-level password that restricts printing or editing but not opening can usually be processed without any issue.

Can I merge PDFs created from different sources?

Yes. This tool merges PDFs regardless of how they were originally created. You can combine a PDF exported from Microsoft Word, a scanned document, a PDF generated from a PowerPoint presentation, a downloaded bank statement, and an image-based PDF all into a single file. Convert any non-PDF source files first using our Word to PDF, Excel to PDF, PowerPoint to PDF, CSV to PDF, TXT to PDF, or Image to PDF tools, then merge the results here.

Are my uploaded files private and secure?

Your privacy is fully protected throughout the process. Files are transferred to our servers over an encrypted TLS connection — the same security standard used by banking websites and financial institutions. Once your merged PDF is generated and ready to download, all uploaded source files and the output file are automatically and permanently deleted from our servers. We do not read, store, index, or share your document content under any circumstances. No account is required, so there is no user profile, upload history, or session data linked to your files.

Do I need to install any software?

Nothing at all. Convixy runs entirely in your browser and all processing happens on our server. There is no desktop application to download, no browser plugin or extension to install, and no dependency on having any PDF software on your device. It works on Windows, macOS, Linux, Android and iOS — just open the page, upload your PDFs, and download the merged result.

More PDF Tools You Might Need

Once you have your merged PDF, Convixy has everything you need to manage it further:

• Compress PDF — Reduce the file size of your merged PDF before emailing or uploading it to a portal with a size limit.
• Split PDF — Extract specific pages or sections from your merged PDF if you need to share only part of it later.
• Word to PDF — Convert DOC and DOCX files into PDF before merging them with other documents.
• Excel to PDF — Turn spreadsheets into PDF documents ready to be combined.
• PowerPoint to PDF — Export presentation slides to PDF and merge them with other files.
• CSV to PDF — Convert CSV data files to PDF and include them in your merged document.
• TXT to PDF — Turn plain text files into PDF pages ready for merging.
• Image to PDF — Convert JPG, PNG, or WEBP images into a PDF and merge it with your other files.