Contrary to how it looks on the surface, the Tinder algorithm is a complex piece of engineering. Unlike a traditional dating site where multiple profiles are accessable at any given time, Tinder only shows you one profile at a time. This means that the order and type of these profiles is imperitive to the success of the app.
What do we know?
1. The app can only show you one person at a time, but in any given area there are thousands of people using it.
2. The app would be ineffective if it showed the same list of people in the same order to everyone, and so an algorithm is necessary to intelligently divide the profiles for different groups.
3. The app seems to be able to show you attractive women/men at a much higher rate then other dating apps.
4. The app shows a different ratio of attractive people or unattractive people to different users.
5. The ordering of matches has changed substantially a few times since I started using Tinder in 2013. (This is conclusive proof that there is some sort of algorithm behind who's profiles are shown, to whom, and when. )
How matches are currently displayed:
Currently the app shuffles the deck in a very predictable way. The first 10-15 cards (it seems to be slightly random) it shows you upon signing in are of non matches. These first cards will also be significantly more attractive than the general population of tinder users as a whole. After this, if you have a high number of waiting matches, tinder will show you mostly users you've matched with with some non-matches in between. If you have a low number of matches, tinder will continue to show you non-matches, but much less attractive than the first group.
So why would Tinder mostly show you attractive users upfront?
This is simple. Showing you attractive users creates the perception that meeting attractive users from Tinder is a possibility. Even though you don't match with these users, you know there are attractive users on Tinder. If the app was truly randomized, you would see mostly average users, which would skew your perception of the value of the app negatively.
Why would they make sure that your first few swipes are not matches?
The previous iteration of the app used to show you all your matches upfront. I have two theories for why this changed. The first is that I think many attractive women got to the point where everyone they swiped was a match. This is a detriment to the gamification, the feeling of chance you get when you swipe and you don't know whether it's going to be a match or not. This leads to fatigue. The second reason for this was to get you to swipe on more people. By forcing every user to swipe through 10 people before getting your matches, you're now increasing the number of likes in the network as a whole.
This was the big element of my previous post which I still think is still relevant.
So we've established that one of the pieces of data we know is that Tinder shows you more attractive people for the first few swipes or so after logging in.
Behind the scenes it's clear that to do this they have to determine which users are most attractive. It's not like they can comb through each profile manually and determine attractiveness, so they likely use the algorithm to determine your attractiveness. You could call it an attractiveness or desirableness score, but basically it's your perceived value on the network.
How does it work then? I don't think it's as simple as having the "most likes" because that would weigh the algorithm in favor of people who have been on Tinder longer, and would favor people who like more people themselves. It could be the % of people who like you out of the number of times your picture is shown to people. However, I think this is too simplistic as well, as it doesn't mirror real life, and would lead to a regression to the mean. Different people have different standards, and thus, would rate differently. For instance a person with very low attractiveness, who's profile is shown to other people of low attractiveness, would be rated highly, similarly, a person of high attractiveness, who's profiles are shown to other people of high attractiveness, might be rated lower.
Therefore, I think Tinder values "likes" from people with a higher attractiveness rating themselves as being of higher value, than likes from people with a lower attractiveness rating. This creates a system of "voting" where users votes are weighted depending on their value to the network.
The unfortunate result of this system is that if you are more attractive, you are more likely to be shown more attractive profiles and be shown to other people with more attractive profiles. I've tested this in the past, where when I have less attractive profile pictures I am shown less attractive matches, and visa versa. Tinder has a vested interest in creating matches because that's where the value lies, and it's been studied that people tend to gravitate most to the people they consider to be on their same level of attractiveness.
How active you are determines when you are pushed to the top of the stack
This has significantly changed since I originally wrote this answer. Initially, I thought that the app would display your profile more often depending on how active you are (remember, only one profile can be shown at a time out of the stack, but there are thousands of users at any one time). I think this is true, but I think I didn't understand all the elements involved.
When you first sign in, you are likely shown to a bunch of people who are online at the same time you are. By watching the sign in times of my matches, I can see that when I'm logged into the app and online, I'll get a bunch of matches (after a lag time of a few minutes) that were active around the same time as I was. The lag time is because tinder is showing your profile to people, so these matches need time to build up. The reasoning for doing this is clear - people who are online and active at the same time are most likely to have a conversation. Therefore, logging in frequently is in your best interest to have your profile displayed to as many people as possible and increase your matches.
Secondly, we have to deal with matches that happen while you're signed off. I'm not sure if this is a gradual scale or if there is a cutoff, but it's clear that after a certain period of time your profile will stop being shown in rotation. I've stopped using tinder for periods ranging from a month to a year, and every time I do that when I sign on I only have brand new matches (again, roughly estimated by last active time)**. I think what's possible is the longer since you've been active, the less often your profile is shown, until it's never shown anymore. But the second you log back in, Tinder goes crazy trying to get you matches so you feel like you had a lot of matches waiting for you all along! The other piece of evidence I have for this is most profiles you are shown have a last active date of between a few minutes to a few days, and a few weeks at most. The reason for this is clear, again. If Tinder was showing people inactive profiles, less conversations would happen, reducing it's value.
This is where it gets a little fuzzy, but I still stand by this as important. My theory is that the third part of the algorithm is swipes, or how often to you swipe out of the number of profiles you are shown? Are you the type of person that doesn't like anyone that likes you (aka you have too high standards?) or are you the type of person that likes everyone and their mother (standards too low).
This is an important metric to have for effectiveness of tinder. If you're the person who is liking everyone, obviously Tinder doesn't want you to be top of everyone's list, so they would penalize you for that. Opposite is true with being picky, if you're too picky, you won't be shown to enough people, so they'll probably increase your odds of being shown higher in people's stacks.
What does this mean for how you use the app?
The most important things to do in my opinion are:
1. Track how attractive the app perceives you to be. If you feel like you're being shown a lot of users that are not very attractive (irregardless of # of matches), it's likely the app things you're not very attractive as well. Improve your pictures and your profile and you should see this change.
2. Stay active. It seems like being active is the quickest way to get to the top of peoples stacks, especially while you are actively on the app. Going on the app more frequently and swiping only a few times will net you more matches than going on once a week and swiping hundreds of times.
Finally, there's the new elements of "Super Likes", but Tinder has been very transparent with how those work. If you Super Like, you're essentially jumping the rest of the parameters and getting pushed to the top of the stack.