Your question made me curious so I tried to see what information about onion sites is available. It’s hard to measure onions sites by design, but https://99fir

Your question made me curious so I tried to see what information about onion sites is available. It’s hard to measure onions sites by design, but https://99firms.com/research/tor-stats https://99firms.com/research/tor-stats Says there seem to be about 65k onion sites. This site: https://protectchildren.ca/en/press-and-media/blog/2025/tor-backgrounder https://protectchildren.ca/en/press-and-media/blog/2025/tor-... Has some varying numbers depending on the observation time, but in final month listed saw 30k sites that had they identified as having CSAM. I’m not sure how accurate either number is or if they are directly comparable but that would be a 50% of all onion sites ballpark. Not sure how to measure general sites vs dedicated abuse sites.