Frequently Asked Questions
Everything you need to know about PDFMerger.io.
Does PDFMerger.io upload my files to a server?
No. Every tool on PDFMerger.io runs entirely in your browser using JavaScript libraries (pdf-lib and pdfjs-dist). Your files are never sent to any server, stored anywhere, or seen by anyone. The processing happens on your own device — when you close the tab, the files are gone.
How do I merge PDFs without uploading them?
Open PDFMerger.io in any modern browser, drag and drop your PDF files onto the merge tool (or click to select them), reorder them if needed, then click "Merge PDF". The merged file is generated locally and downloaded directly to your device. No upload, no account, no waiting.
What is the maximum file size for merging PDFs?
There is no hard server-side limit because no files are uploaded. The practical limit is your browser's available memory. Most modern devices handle PDFs totalling 100–200 MB comfortably. Very large files (500 MB+) may slow down or fail depending on your device. If you hit issues, try splitting the job into smaller batches using the batch merge feature.
Can I merge password-protected PDFs?
PDFMerger.io cannot merge PDFs that are locked with an owner or user password — the PDF needs to be unlocked first. Use the Unlock PDF tool (pdfmerger.io/unlock) to remove the password, then merge the unlocked files.
Does merging PDFs reduce quality or resolution?
No. PDFMerger.io uses pdf-lib to merge files at the structural level — it combines the page objects from each PDF without re-encoding images, fonts, or any other content. The output is identical in quality to the originals.
How do I merge PDFs on iPhone or iPad?
Open PDFMerger.io in Safari on iOS. The tool works in mobile browsers — tap "Select Files" to choose your PDFs from the Files app or iCloud, then tap "Merge PDF". The merged file will be saved to your Downloads folder or you can share it directly.
How do I merge PDFs on Mac?
Open PDFMerger.io in Chrome, Safari, or Firefox on your Mac. Drag and drop your PDFs into the merge area or click to browse. Reorder by dragging, then click "Merge PDF" to download the combined file. No software installation needed.
How do I merge PDFs on a Chromebook?
Open PDFMerger.io in Chrome on your Chromebook. The tool is fully browser-based so it works perfectly on ChromeOS. Select your PDFs from the Files app, merge, and download.
Can I combine more than two PDFs at once?
Yes. You can add as many PDFs as you like. There is no limit on the number of files — the practical constraint is available browser memory. Drag them all in at once or add them one by one, reorder as needed, then merge.
Is PDFMerger.io free?
Yes, completely free. There are no subscriptions, no premium tiers, no watermarks, and no sign-up required. The site is supported by voluntary donations (Buy Me a Coffee).
What browsers are supported?
PDFMerger.io works in all modern browsers: Chrome, Firefox, Safari, Edge, and Brave — on desktop and mobile. Internet Explorer is not supported.
Why is my merged PDF larger than the original files combined?
This can happen when the original PDFs contain embedded resources (fonts, images, ICC profiles) that are duplicated across the files. Merging at the structural level preserves all embedded content to maintain quality. To reduce file size, run the merged PDF through the Compress tool after merging.
Can I reorder pages before merging?
Yes. After adding your files, drag them into the order you want before clicking Merge. The merged PDF will follow that order. Page-level reordering within a single file is not currently supported in the merge tool — use the Remove Pages or Rotate tools to adjust individual files first.
What is the difference between merging PDFs and combining them?
"Merging", "combining", and "joining" PDFs all refer to the same thing: taking two or more PDF files and producing a single PDF that contains all their pages in sequence.
Can I convert a PDF to Word?
Yes — use the PDF to Word tool (pdfmerger.io/pdf-to-word). It extracts the text content from the PDF into a .docx file. Note that complex formatting, tables, and embedded images may not be perfectly reproduced, as the conversion is text-extraction based and runs entirely in the browser.