Instagram has met with runaway success over the last year, which has helped settle the debate over the service's filters — like them or not, they're not going anywhere anytime soon. Despite the filter's popularity, plenty of users see fit to proclaim their photo's authenticity by using the #nofilter hashtag, a mark that symbolizes that your photo has been posted without any modification save Instagram's default square crop. If you've ever stared at your friends' photos and thought they were just too saturated or faux-vintage to be real, however, a new Tumblr site called Filter Fakers has you covered. The site's main feed shows off fake #nofilter pictures, complete with the username and actual filter applied to the photo.

It's not clear how exactly the site determines fakes, but there's a helpful page that breaks down exactly what each filter does to a photo, complete with helpful "before and after" images. And if you just want to test some of your friends' photos for yourself, you can drop the URL of an Instagram filter into the tool and it'll tell you whether or not it's a fake. Sure, faking a #nofilter pic on Instagram is a victimless crime — but if you've ever wanted to catch your too-cool friends in the act, Filter Fakers might be able to help you out.