Free Software & Apps

How to Merge, Split and Compress PDF Files for Free (Online and Offline)

Step-by-step ways to merge, split, compress and convert PDFs without paying, using free online tools for quick jobs and offline desktop apps for private documents.

By Welcome Free Tools Editors October 6, 2026 6 min read

How to Merge, Split and Compress PDF Files for Free (Online and Offline)

Need to combine a few PDFs into one file, pull out a couple of pages or shrink a document so it fits an email attachment? You do not need paid software for any of that. In this guide you will learn how to merge, split, compress and convert PDF files for free, both online in your browser and offline on your own computer, using tools whose official sources we have verified.

Quick answer: For a quick job, use a free online tool such as PDF24 Tools or iLovePDF. For private or confidential documents, use PDFsam Basic, a free desktop app for Windows, macOS and Linux that works fully offline. If you only need to read PDFs on Windows, Sumatra PDF is a fast, free reader.

Online or offline: which should you use?

Online PDF tools are the fastest way to get a job done. There is nothing to install, they work on any computer, and many also offer mobile apps. The trade-off is that your file is uploaded to the service to be processed.

Desktop tools keep everything on your computer. That makes them the better choice for contracts, IDs, bank statements, medical letters or anything else you would not want to upload. They also work without an internet connection once installed.

A simple rule: use online tools for everyday documents, and offline tools for anything confidential.

The free PDF tools in this guide

Tool	Pricing	Runs on	Works offline?	Best for
PDF24 Tools	Completely free	Web, Windows	Yes, with the free Windows app	Merging, compressing, converting and editing
iLovePDF	Free, optional Premium	Web, Android, iOS	No	Quick tasks in the browser or on your phone
PDFsam Basic	Free and open source	Windows, macOS, Linux	Yes	Merging, splitting and reordering private files
Sumatra PDF	Free and open source	Windows	Yes	Fast, lightweight PDF and e-book reading

How to merge PDF files for free

Online with PDF24 Tools

Open PDF24 Tools and choose the Merge PDF tool.
Add your files by dragging them onto the page or using the file picker.
Drag the files into the order you want them to appear.
Start the merge, then download the combined PDF.

According to PDF24’s official site, its online tools can be used without registration, without limits and without adding watermarks to your files.

Offline with PDFsam Basic

Download PDFsam Basic from its official website and install it.
Open the app and choose Merge.
Add your PDFs and arrange them in the right order.
Choose where to save the new file, then run the task.

Because PDFsam Basic works fully offline, your documents never leave your computer.

How to split a PDF or extract pages

PDFsam Basic can split a PDF into separate documents by page numbers, by bookmarks or by file size, and it can extract just the pages you choose into a new file. This is handy for pulling a single invoice out of a long statement, or breaking a large scanned document into chapters.

If you prefer working in the browser, both PDF24 Tools and iLovePDF include split tools that follow the same upload, choose pages and download pattern.

How to compress a large PDF

Scanned documents and PDFs full of photos can be too large to email or upload to a form. The compress tools in PDF24 Tools and iLovePDF reduce file size, mostly by optimising the images inside the document.

Start with the default or recommended compression level and check the result before sending it.
Stronger compression gives smaller files but can make images and scanned text look blurry.
Keep your original file until you are happy with the compressed copy.

iLovePDF’s free use has limits on file size and the number of tasks; its optional Premium plan raises those limits. If you hit a limit, try PDF24 Tools instead.

How to convert PDF to Word and back

PDF24 Tools and iLovePDF both convert PDFs to and from Word, Excel, PowerPoint and image formats. Converting a Word document to PDF usually keeps the layout exactly. Going the other way, from PDF to Word, works best with simple text documents; complex layouts with columns, tables or unusual fonts may need some tidying afterwards.

PDF24 can also recognise text in scanned documents, which helps when you need to copy text out of a scan.

Rotate, reorder and combine scanned pages

Scanners often produce sideways pages, or separate files for the front and back of double-sided paperwork. PDFsam Basic can rotate pages and mix pages from two documents, which is exactly what you need to combine separately scanned front and back pages into one correctly ordered file.

Just need to read PDFs?

If you mainly open and read documents on Windows, Sumatra PDF is a small, fast reader that also opens EPUB and MOBI e-books, comic book archives (CBZ and CBR), DjVu and XPS files. It supports tabs, has a portable version that runs from a USB drive, and its official website states that it contains no ads. It is a reader rather than an editor, so use one of the tools above to change files.

Keep your documents private

Use an offline tool such as PDFsam Basic, or PDF24’s free Windows app, for confidential documents.
Before uploading to an online service, read its privacy policy so you know how long files are kept.
Only use the official websites and official app-store listings. Copycat “free PDF converter” sites are common.
Be wary of browser extensions or installers that promise PDF features but ask for broad permissions. Our guide to downloading free software safely explains what to look out for.

Which free PDF tool should you choose?

Want the most features without paying? PDF24 Tools is completely free and covers merging, compressing, converting, editing, signing and password protection.
Working on your phone? iLovePDF has official Android and iPhone apps as well as its website.
Handling private documents, or using a Mac or Linux? PDFsam Basic runs offline on Windows, macOS and Linux.
Only reading? Sumatra PDF is the lightest option on Windows.

For more options, see our curated collection of the best free PDF tools, which explains how each listing was selected.

Frequently asked questions

Can I merge PDF files for free without a watermark?

Yes. PDF24’s official site says its online tools do not add watermarks, and PDFsam Basic merges files on your own computer for free.

Is it safe to upload PDFs to online tools?

For everyday documents, reputable online tools are convenient. For confidential files, use an offline desktop tool such as PDFsam Basic so the document never leaves your computer.

What is a good free PDF tool for Mac?

PDFsam Basic runs on macOS and works offline. PDF24 Tools and iLovePDF also work in any browser on a Mac.

Can I edit a PDF for free?

PDF24 Tools includes free tools to edit, sign and protect PDF files, as well as page tools such as rotating, deleting and numbering pages.

Do I need to create an account?

Not for PDF24 Tools, which can be used without registration according to its official site. PDFsam Basic and Sumatra PDF are desktop apps, so there is nothing to sign up for.