Cachety vs PDF24: watermarking your documents online
Updated 11 October 2026
PDF24 is a free, generous set of PDF tools from a Berlin company, with no limits and no registration. Its online watermark tool runs on PDF24's servers in Germany. Cachety is also free, but your file never leaves your device.
In short
PDF24 is a strong free toolbox, and its Windows app, PDF24 Creator, keeps files on your PC. For a quick watermark on an ID document from a phone or a Mac, Cachety avoids the upload and has no adverts or advertising trackers on the page.
Side by side
| Criterion | Cachety | PDF24 |
|---|---|---|
| Where your file is processed | CachetyIn your browser, on your own device.Advantage Cachety | PDF24On PDF24's servers in Germany for the online tool. PDF24 Creator for Windows works on your PC. |
| How long the file is kept | CachetyNever stored anywhere except on your device.Advantage Cachety | PDF24Deleted from the server within one hour, or sooner if you delete it yourself. |
| Price and limits | CachetyFree, no account. | PDF24Free, no limits and no registration. |
| Adverts and trackers | CachetyNo ads or trackers today.Advantage Cachety | PDF24Funded by advertising. Its privacy policy mentions Google AdSense, Google Analytics and Google remarketing. |
| Type of watermark | CachetyText, repeated diagonally across the page, with an optional wave effect. | PDF24Text, with nine positions or fill the page, plus angle and spacing. |
| Can the watermark be stripped out? | CachetyNo simple way: it is blended into the page image. | PDF24Not documented. |
| Blacking out details, password, metadata | CachetyAll in the same screen as the watermark. | PDF24Available as separate tools: Redact, Protect and Remove metadata. |
| One copy per recipient | CachetyYes, up to 20 named copies in one go.Advantage Cachety | PDF24Not offered in the watermark tool. |
| Other PDF tools | CachetyWatermark, mask, combine, password and size only. | PDF24Dozens of free tools, plus a free desktop app for Windows.Advantage PDF24 |
What happens to your file with PDF24 online
PDF24 is open about it: the watermark is added on its servers in the cloud, the servers are in Germany, and files are deleted after one hour. That is a clear, fair policy from an EU company. It still means a copy of your passport or payslip is sent across the internet and stored for up to an hour on a machine you do not control.
Cachety takes a different approach. The page loads once, then everything happens inside your browser. Your document is never sent anywhere, so there is nothing to delete afterwards.
Want proof? Open cachety.com, turn on aeroplane mode and watermark a file. It keeps working because nothing needs the internet.
Where PDF24 is better
PDF24 has dozens of free tools with no limits, from compression to conversion and OCR. On Windows, PDF24 Creator does the work on your own PC, which is a good option for privacy too. Cachety does not convert, compress on its own, or edit PDFs, and has no desktop app.
Where Cachety is better for ID documents
- Works on your device on any system, including iPhone, Android and Mac, with nothing to install.
- No adverts and no advertising trackers on the page.
- Watermark, masking, password and hidden data removal in a single step.
- One named copy per recipient, handy when you apply to several letting agents.
How to do it with Cachety
- 1Open cachety.com.
- 2Add your PDF or photos.
- 3Type who it is for and why, and add today's date.
- 4Download the watermarked copy.
When PDF24 is the better choice
- You use Windows and want a free desktop app that keeps files on your PC.
- You need many other free PDF tools, such as conversion, compression or OCR.
- You want to keep the PDF text selectable after watermarking.
When Cachety is the better choice
- You want to watermark an ID document on a phone or a Mac without uploading it.
- You prefer a page with no adverts or advertising trackers.
- You need masking, a password and one copy per recipient in one go.
Frequently asked questions
- Does PDF24 upload my files?
- Yes, for its online tools. PDF24 says the watermark is added on its servers in Germany and files are deleted after one hour. Its Windows app, PDF24 Creator, keeps files on your PC.
- Is PDF24 safe to use for a passport?
- PDF24 is an EU company with a clear deletion policy. Whether that is enough is up to you. If you would rather your passport never left your device, a browser-only tool like Cachety avoids the question.
- Is PDF24 really free?
- Yes. PDF24 says its tools are free with no limits, funded by advertising. Cachety is also free, with no ads or trackers today.
Sources
Facts checked on 11 October 2026 on each publisher's public pages. Services change: if something here is out of date, tell us on GitHub and we will fix it.
Written by the author of Cachety. We aim to be factual and fair: every claim about another tool links to its source.