PDF24 Tools is free and generous, which is rare in this space. Its weakness is platform: the full feature set lives in a Windows-only desktop app, and the online tools upload your files to German servers for processing. If you are on macOS, Linux, a Chromebook, or a phone — or if you handle confidential documents — the experience is a step down.
PDFMerger.io works the same on every device and never uploads a file. Here is the side-by-side.
| Feature | PDFMerger.io | PDF24 Free | PDF24 Paid |
|---|---|---|---|
| Price | Free forever | Free | — |
| Files uploaded to a server | Never | Online tools: yes | Desktop: no |
| Installation required | None (web) | None for online tools | Windows installer |
| Works on Mac / Linux / Chromebook | Yes | Limited (web only) | No |
| Works on mobile | Yes | Limited | No |
| Signup required | No | No | No |
| Ads | Minimal | Shown | None |
| Works offline after load | Yes | No (online) | Yes (desktop) |
| Merge / split / rotate / compress | Yes | Yes | Yes |
| PDF ↔ Word / JPG / PNG | Yes | Yes | Yes |
| Markdown to PDF | Yes | No | No |
| PDF Malware Scanner | Yes | No | No |
| OCR | Not yet | Basic | Yes |
| PDF editor | No | Limited | Yes |
Being honest — PDFMerger.io does not try to replace every feature. PDF24 wins on:
For everything else — merge, split, compress, rotate, unlock, convert — browser-local is faster and more private.
Merging 8 × 3 MB PDFs via the online tool:
| Tool | Upload | Process | Total |
|---|---|---|---|
| PDFMerger.io | — | 1.2s | 1.2s |
| PDF24 | 1.7s | 1.5s | 3.2s |
The PDF24 desktop app is very fast, but only for Windows users. On any other platform, their online tool is the only option and upload time becomes the bottleneck.
PDF24 is built primarily as a Windows tool. The online version is a convenience, not the full product. macOS, Linux, and Chromebook users are stuck with the limited online version, which uploads every file. Mobile users have an even worse experience. PDFMerger.io is designed browser-first and works identically on every platform.
PDF24 Desktop processes locally — privacy-safe. PDF24 Online uploads your file to tools.pdf24.org, processes it in Germany, and deletes it within 30 minutes. PDFMerger.io never uploads. For confidential files, PDF24 Desktop and PDFMerger.io are both safe; PDF24 Online is not.
If you are on Windows, want a full PDF editor with OCR, and do not mind installing desktop software, PDF24 Desktop is genuinely good and free. For cross-platform users and anyone who prefers not to install software, PDFMerger.io covers the common tasks in one browser tab.
Yes. PDFMerger.io is a browser-based PDF24 alternative that works identically on macOS, Linux, ChromeOS, Windows, Android, and iOS. No installation required.
Yes. PDF24 online tools upload every file to their servers in Germany for processing and delete them within 30 minutes. Only the Windows desktop app processes locally. PDFMerger.io never uploads.
Yes. PDFMerger.io runs in any modern browser, including Chrome on ChromeOS. All processing is local to your device.
No. It is a web application. Open the page, drop your PDFs, done. You can also install it as a Progressive Web App for offline use if you prefer.
PDF24 is a reputable German company and their tools are safe to use. For sensitive documents, prefer their desktop app over the online tools, or use a fully client-side alternative like PDFMerger.io.
Drop your PDFs. They never leave your browser.
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