https://imgur.com/
https://postimages.org/
Are two that I use. Both are free without registration. Imgur seems to be better, I've had postimage pics go missing after a while, but imgur seems to limit the size. One caveat is to make a record of the web address of the picture, both rename them and you'd play hell trying to find them without the new full name, I keep a spreadsheet just for that. I guess imgur has a ton of ads on phones, but I don't see them on the PC, however sooner or later both are likely to go away, you can only give stuff away free for so long. There's others like Flickr and Google but they make it a pain to use on a forum, they really want you to go to the page it's on. Photobucket was free, then went to $400 a year, then dropped way down but I don't think free. I would avoid them.