I Built a Free Batch Watermark Tool in Under 30 Minutes

2026-10-14 · Open Source · By Toluwani Moses Bakare

Being a developer changes the way you see the world. Every inconvenience starts to look like an app waiting to be built.

The problem at church

For a while at church, we had been taking photos with a phone and adding a watermark to every single image by hand before posting. It worked, but it was slow and repetitive, and it sometimes delayed getting content out.

Then I asked myself: "Why am I doing this manually when I literally build solutions to problems?"

So I built Watermarqa

With the help of AI and a clear idea of what I wanted, I built Watermarqa in under 30 minutes.

Here is what it does:

• Watermarks lots of images at once. Drop in a batch and it does the whole lot.
• Keeps your images on your device. Nothing is uploaded to a server. No uploads, no servers, no tracking.
• Lets you place the watermark where you want it. You control the text, size, opacity and alignment, from top-left to center to bottom-right.
• Downloads everything as a ZIP when you are done.

It is built with plain HTML, CSS and JavaScript. The watermark is drawn onto each image with the HTML5 Canvas, and the results are packed into a ZIP at the end. There is no backend, which is exactly why your photos never leave your browser.

Free and open source

Watermarqa is completely free and open source. You can try Watermarqa here or read the code on GitHub.

My little gift to everyone. I hope it saves you as much time as it is already saving me.

The lesson

Sometimes the biggest productivity boost is not working harder. It is taking a few minutes to build the tool you wish you had.

So build things that solve your own problems first. Chances are they will solve someone else's too.

If you have a problem like this in your business or your church and want a tool built for it, get in touch. You can also see more of what I have built on my projects page.