Safe for Work Checker as a Service

Warning: Only people who are of legal age of maturity should view this website. The website contains pixels of a butt.

How does this work exactly? The image uploader does not appear to work like a regular uploader. It just creates a file extension in the upload url. Is any file even uploaded to this service or is it just checked with the service? The service itself says the images are deleted immediately after. Maybe instead of using this, I should use local ones. Are there any good local NSFW checkers that you users know of? Thank you.

What are you trying to do?

I am trying to find a good safe for work checker that detects NSFW or safe for work for fictional content. I would rather not use an online service.