Image Watermark
Add a text watermark with position and opacity controls.
Drag & drop a file here, or browse
Your result will appear here. Processing happens entirely in your browser.
How to Use Image Watermark
- 1
Select or Upload
Choose or drag-and-drop your file directly into the Image Watermark workspace.
- 2
Configure & Process
Customize parameters, set preferences, and preview your output in real-time.
- 3
Download Instantly
Save your processed file directly to your local device with zero server uploads.
About Image Watermark
Add a text watermark with position and opacity controls. This utility processes files locally inside your browser using modern Web APIs (WebAssembly and Canvas). Your documents and images are never uploaded to any remote cloud server, providing total confidentiality for sensitive files.
Zero Server Upload
Files remain on your local disk at all times.
Unlimited Free Usage
No file size limits, paywalls, or daily caps.
Frequently Asked Questions
Is this Image Watermark safe and private to use?
Yes. All processing happens 100% locally on your computer inside your web browser using client-side JavaScript. Your files and data are never sent to any external server.
Do I need to create an account or pay to use this tool?
No. All 60 tools on NS Ascertain Toolkit are completely free with no registration, no subscription, and no usage limits.
Does this tool work on mobile devices and Macs?
Yes. The tool runs on any modern browser including Chrome, Safari, Firefox, and Edge across Windows, macOS, iOS, and Android.