PhotoStack can import multiple photos from your local storage. From there, you can resize images, set the desired format, add a watermark, and remove EXIF data.
Afterwards, just press the Export button, and all your photos will be ready to go.
If you need to protect your images, you can easily create watermarks in PhotoStack for later use. You can set the image, positioning, opacity, size, and more. If you've ever used Adobe Lightroom, you'll feel right at home.
Once you're done creating a watermark, you can save it to your device's local storage for later use, and even export the data to a file for use on another device.
PhotoStack doesn't lock you down to certain platforms or require a monthly subscription. It runs on everything with a modern web browser.
All the source code is available on GitHub under the GPLv3 license. If you're a developer, you can help fix bugs, or even create your own fork of PhotoStack.
All image processing is done locally in your browser. Your images are never uploaded anywhere, and the only data collected by PhotoStack is basic analytics.
PhotoStack can function entirely offline on most browsers, thanks to a web technology called Service Workers. When you run PhotoStack for the first time, the app is saved to your device's storage, so typing in "photostack.app" will always work — even when you're away from Wi-Fi.
PhotoStack works on any modern browser or platform that supports modern web features, including Chrome, Firefox, Opera, Microsoft Edge, and others.
For devices and browsers that aren't up-to-date, you can still use PhotoStack Classic. It has most of the same features, but works on browsers as old as Internet Explorer 10.