Like the other recommended Python scripts: this will generate a folder with an index HTML file and a second folder with your images.  You can browse your blog on your computer as if is was a website.  This format is not something you can easily import into another blogging platform (ex: Wordpress). You can upload it to your own website (ex: https://zinedom.org/zinedom-tumblr/index.html )  as a static archive but check with the website company on storage space, bandwidth, adult content limits.

From the article:

“it’s not a nice clean export in some standard format that you could use to easily import all your posts into another content management system or blogging tool. HTML files and related images are scattered through a system of directories and subdirectories that, while logical, may not be the simplest thing to work with. Using the data you’ve got, a clever computer person could generate an XHTML document (or something similar) that could be semi-automatically imported into (say) WordPress. But it would take parsing; it would take work. Figuring out how to take the copy you just made and turn it back into a non-Tumblr website is a solvable problem, but how easy or hard it might be to actually do it depends on your access to computer expertise and tools. For now, you’re safe in the knowledge that you’ve got all the posts you’ve made this past however-many years. You’ve got the images, you’ve got their metadata (any tags you set for them and any credits you may have reblogged or included) and you’ve got the clever things you said about them, all, safe on your hard drive.

Now would be a good time to back up your hard drive. I’m just sayin’.“