Online without an upload
The editor is a static web page. JavaScript loads pdf-lib and pdf.js from this site, then reads the file you selected through the browser file picker. There is no API call that posts the PDF. After the first load you can even disconnect the network and still download a watermarked copy.
When a desktop app is still better
Install Acrobat or PDF-XChange if you watermark hundreds of files a day, need action wizards, or must overlay a company logo PNG. For a one-off confidential mark on a laptop you do not administer, a browser tab is faster and leaves no installer behind.
Browser support
Current Chrome, Edge, Firefox, and Safari on Windows, macOS, and Linux all work. iOS Safari and Android Chrome work for typical document sizes; very large scanned files may hit mobile memory limits.
Frequently asked questions
Does “online” mean you can see my file?
No. Online here means the interface is a website. The PDF is not transmitted.
Can I use it on a locked-down work PC?
If the browser can run JavaScript and open local files, yes. No admin install is required.
Use this when you want an online workflow without giving a SaaS product a copy of the document.
Open the online toolRelated pages
Free PDF watermark tool
Free PDF watermark tool. No account, no page cap, no file upload. Add text watermarks in your browser. Files never leave your device. Download instantly.
Add a watermark to a PDF
Add a watermark to a PDF online. Free, no account, no file upload. Vector text on every page. Files stay in your browser. Download in seconds.
How to watermark a PDF on Mac
How to watermark a PDF on Mac. Preview has no watermark tool. Use this free browser method, Acrobat Pro, or a Quartz workaround. No file upload here.
How to watermark a PDF on iPhone or Android
How to watermark a PDF on iPhone or Android in the mobile browser. No App Store install, no account, no upload. Memory limits apply to large scans.
Watermark a PDF in your browser
Add a text watermark to a PDF online. Free, no account, no file upload. Files stay in your browser. Set text, opacity, and position on every page.