My bookmark manager SemanticScuttle is able to show screenshots for bookmarked websites, but always relied on an external service to generate them. The service shut down now - time to look for an alternative.
There are several dozen screenshot services on the internet; some have free plans that would allow you to re-enable screenshots on your self-hosted SemanticScuttle instance for free. But unfortunately this means registering at yet another service and being again dependent. Time for something new!
phancap
Over the last three weeks, I built phancap - a self-hosted website screenshot service. With it, your bookmark manager will never have to depend on an external service again.
It's easy to setup: Simply drop the .phar in your webserver's document root, install xvfb-run, cutycapt and imagemagick, and you're done.
It supports JPG, PNG and PDF output formats. PNG is ideal for screenshots, while full-text PDF is nice for long-time archiving of web pages.
You may configure the browser and thumbnail size, and can choose between a fixed height and full-page screenshots. Authentication may be enabled to prevent others using your server resources.
Download it or grab the source code (github mirror).