Hey, kids! Sparkline! sparkline graph of RSS subscribers That’s the estimated count of RSS subscribers to this blog. This is scaled and goes back to about the beginning of the year.

Not perfect—if a desktop RSS user switches clients or networks they get counted twice, but it does use the subscriber counts that services such as Feedbin and NewsBlur pass in the User-Agent header. And I think it fluctuates based on people trying different clients, scraper runs, and other trends. (When I get on “Hacker News” for something, there is always a bunch of weirdly configured bot traffic. A lot of it looks like requests for LLM-generated URLs that I might have used but never did.)

This is basically following the method in Easy SVG sparklines by Alex Plescan, except that in order to work as an img, the SVG file needs an XML namespace. See SVG Not Showing in Browser? Fix It in 30 Seconds on the SVG Genie blog.

Update: A StackOverflow answer from Francisco de Javier covers how to invert the image colors to support dark mode. I have the following in the CSS stylesheet:

@media (prefers-color-scheme: dark) {
    .sparkline {
        filter: invert(100%);
    }
}

This does not give me a perfect color match for the text color, but it’s close enough for now.