http://search34.org/ has been doing this for a few years.

As the creator described it to me: it does a search, and a parallel search with porn filters, and returns the diff.

It appears this one works the same way. As the About page explains:

    Search for images and only get the unsafe ones. That's
    Filther in a nutshell. We give you only the stuff that
    Safe Search Filters leave out. This search is strictly
    NSFW. And let's be honest, this is what the internet
    was made for.

I guess the best use of this is to demonstrate how many false positives traditional filters have...

Even though you're making a joke it's actually interesting. The only search I've done (to see how ridiculous the internet is?) is "sunny walks on the beach". I chose the "destroyer of children" filter and once you get past maybe 10-15 dirty pictures its incredible the stuff that is actually completely safe for work that I guess Google somehow filters out lol

Try searching for "wax". The pictures alternate between what I expected and pictures of random buildings.

Hmm, don't try searching for wax on second thoughts. I scrolled a bit further and there's a tonne of man-on-man bondage (unless that's what you'd like to see).

The very safe pics appearing in the middle of the nsfw ones came from domains with otherwise adult content (a chicken noodle bowl on i.e. pussyleaks.com) . In hindsight it seems obvious, I never thaught about the halo effect of adult content hiding the other contents from normal searches.

A bowl of noodles on an otherwise porn site is not a big deal, but if there was an interview site with half of it's contents nsfw (say they interviewed nudists or exibitionists) it would have to deal with the issue.

I know a bunch of site that use different domains to segregate contents(dmm.com and dmm.co.jp for instance), but I wonder what other ways there are to keep your safe content searchable while having an nsfw portion on the same site.

The trending search term "noodles" seems to only give SFW pics of noodles or completely unrelated NSFW results.

I noticed that too. Which I guess means there's potentially a whole world of content filtered out as being NSFW when really it's fine...

This doesn't really work. My searches are very unrelated.

The results are terrible, even using actual names from models gets you random results.

I even tried kurt cobain on "Destroyer of childhoods" mode and didn't get even one copy of the infamous coroner's picture.

On google is on top of all result with safesearch off.

You've answered your own question in that last sentence - if Google isn't filtering it using safesearch then it won't appear on Filther

The popular searches terrify me.

"penis" barely returns any penii

it did pretty terribly at 'fractal'.

Any plans to open source it?

What reason is there to open source this? The whole algorithm is practically explained here, https://news.ycombinator.com/item?id=6703714

Can I get an "amen"

Wow

Much plus

so filth

many ponies

Y'know, I used the term 'Pony' because I thought it'd be the most innocent thing I could search for. There's nothing sinister about ponies.

This is one of those instances where I could not have been any more wrong. Eyebleach, please!

Might want to capitalize that warning, and add nsfw. I'm very happy one of my kids was not looking over my shoulder. I guess I'm with the late Mr Jobs on this one --thinking this is not necessarily advancing the internet or making the world a better place.

Even if you clicked on the link, it's a completely innocuous page. It explains what it does, but it doesn't use any foul language doing that.

What's the risk of having one of your kids looking over your shoulder?

I tend to not exercise any caution clicking links on hacker news, and since time is "the" essence, really; I use a click and "see for myself if this is interesting" approach, since there's more noise here these days. well I clicked and clicked again on one of the words under the search box. I'm sitting in the middle of the kitchen where my 4-7 yrs old children are roaming around. I often show them computer stuff on here so it would have been completely normal for them to be looking in on this browsing session. I was in for a world of shock; backed up real quick and understood what nws meant. I had seen the nsfw tag before but not nws. Thanks for the downvotes tho.

Mr Jobs opposed a product that was invented after his death?

I think it was a sore point for a lot of people, and a question mark for me why Apple and mr Jobs was imposing a sort of censorship on iOS apps with regards to explicit content. Well I got real world case of how something useful to some can be damageable to kids on a platform where this is totally unexpected: HN.

Ask yourself: what would Jobs do?

Often did that as a younger entrepreneur. Paid off, thank you. He undeniably had the sharpest eye of his generation to find the angle that work with the market.