A browser-based batch image watermarking tool — add custom text or logo watermarks to hundreds of images at once. Runs 100% locally, no uploads, no server, no limits.
Watermark Builder is a fully client-side tool for batch watermarking images. Every tool I found either had file size limits, uploaded images to a remote server, or charged for bulk export. So I built this instead.
Everything runs in your browser using the Canvas API — your images never leave your machine. Drop up to 100 images, pick a watermark layout, adjust opacity and size, and download a ZIP. No account, no upload, no wait.
- ✅ Process up to 100 images in a single batch
- ✅ Use a custom logo/image as watermark
- ✅ 4 placement layouts — triangle, diagonal, corners, horizontal
- ✅ Adjustable opacity and size
- ✅ Export as a ZIP archive with one click
- ✅ 100% local — images never leave your browser
- ✅ No account, no upload, no file size limit
- ✅ Zero dependencies — pure Vanilla JavaScript
| Technology | Role |
|---|---|
| JavaScript (ES6+) | Core processing logic |
| HTML5 Canvas API | Image compositing & watermark rendering |
| JSZip | Client-side ZIP generation |
| HTML5 File API | Local file reading (no upload needed) |
| CSS3 | UI layout & styling |
- Go to alirewa.github.io/watermark-builder
- Drop your images (up to 100 at once)
- Upload your watermark logo or type custom text
- Choose a placement layout and adjust opacity/size
- Click Export ZIP — done!
git clone https://github.com/Alirewa/watermark-builder.git
cd watermark-builder
# Open index.html in your browser — no build step neededDistributed under the MIT License — free to use, modify, and distribute.
Made with ❤️ by Alirewa