Oleg Parashchenko registered tohtml.com back in March 2005 and put the service live in April 2006. If you fancy a look at how it started out, the Wayback Machine first crawled it on the 24th of June 2006, and that original version is still there. It has always done the same core job: paste some code, get nicely coloured HTML back.
We took it over in June 2014 and have looked after it ever since, updating and adding to it bit by bit. The bigger pushes landed in 2015, 2019 and 2024, when I would sit down and add some languages and themes, tidy up a few features, and clear out whatever bugs had piled up in the meantime.
Mid 2026 was the big one. Hundreds of new languages, anonymous stats on what people highlight, a proper set of filters and a few more UI touches, extra colour styles, much better auto-detection, more you can customise, a good chunk of performance work under the hood, and plenty more. Most of what you see today came out of that stretch, and I am still adding to it.
Spot something I have got wrong, or remember a bit of the story I have missed? Drop me a line.