How Does eHarmony Match You? (A Look At the Scientific Algorithm)

Online Dating

How Does eHarmony Match You? (A Look At the Scientific Algorithm)

Hayley Matthews
Hayley Matthews Updated:
Advertiser Disclosure

Advertiser Disclosure is a free online resource that offers valuable content and comparison services to users. To keep this resource 100% free, we receive compensation from many of the offers listed on the site. Along with key review factors, this compensation may impact how and where products appear across the site (including, for example, the order in which they appear). does not include the entire universe of available offers. Editorial opinions expressed on the site are strictly our own and are not provided, endorsed, or approved by advertisers.

Our Editorial Review Policy

Our site is committed to publishing independent, accurate content guided by strict editorial guidelines. Before articles and reviews are published on our site, they undergo a thorough review process performed by a team of independent editors and subject-matter experts to ensure the content’s accuracy, timeliness, and impartiality. Our editorial team is separate and independent of our site’s advertisers, and the opinions they express on our site are their own. To read more about our team members and their editorial backgrounds, please visit our site’s About page.

I love In-N-Out’s secret sauce. I know it’s basically Thousand Island, but it’s amazing. I could drink it like water, and I don’t care how disgusting that sounds. I’ve tried replicating the sauce myself, but I’ve never gotten it to taste quite the same. There’s just something about it that is both magical and irreplaceable.

I feel the same way about how eharmony matches couples and inspires relationships. It can’t be matched by anyone else.

I’m sure you’re familiar with this longstanding dating site — it’s been around since 2000, after all. You’ve probably seen the commercials, heard the jingle, and know a friend or a friend of a friend who has used the site or even found love on it. But what remains a mystery to some singles is exactly how eharmony does its matching. Well, we’re here to let you in on the site’s secret sauce.

To Start Receiving Matches, Take the 29 Dimensions Questionnaire

What makes eharmony so successful and famous? It all starts with its signature 32 Dimensions® of Compatibility Matching Quiz — which was created by Dr. Neil Clark Warren, an American clinical psychologist, Christian theologian, and seminary professor who also co-founded the site.

When you sign up to eharmony, you have to undergo a personality assessment to kick things off. It takes about 20-45 minutes to complete the questionnaire (depending on how much self-examination you want to do during the process), and eharmony goes to great lengths to cover deeper topics than what you’ll find on most other dating sites, including self concept, adaptability, vitality, and conscientiousness.

Here are some of the questions you can expect to answer:

  • What are you passionate about?
  • What two or three things do you enjoy doing with your leisure time?
  • What are the three things you’re thankful for?
  • Are you open to meet someone who already has children?
  • If your best friends had to pick four words to describe you, which four would they pick?

As you can see, eharmony doesn’t just ask your standard yes-or-no questions, so you’re more likely to bare your soul and find your soul mate on the site. For more information about the kinds of questions eharmony could ask you, check out our article here.

eharmony Uses Those Answers to Find Potential Dates

When you’re responding to eharmony’s questions, you’ll want to take your time and really think about your answers — don’t just type the first thing that comes to your mind. Be honest with the site and with yourself because that’ll be better for you in the long run.

The site uses the information from your questionnaire and profile when it’s scouring its user base for potential dates and partners who fit your criteria. Obviously, eharmony won’t disclose every single detail about how the algorithm works, but we can safely assume that what you tell them plays the biggest role in its compatibility scores.

The Site Delivers Match Suggestions to Your Inbox Every Day

Every day, you’ll want to log into eharmony and take a look at the matches the site has sent you. You can expect to receive a handful of suggestions or so, and then the ball is in your court.

Photo of an eHarmony match

Every day, you’ll see profiles of other members in your eharmony inbox. These are the people the site thinks are a good fit for you.

These Daily Matches give you a chance to review compatible members and see if eharmony hit the nail on the head (they probably did). You’ll see the person’s photos, age, location, height, occupation, education level, religion, political standing, and smoking and drinking habits, among other traits, interests, and identifiers.

Note that there are very few search filters (just age, location, and other basics) on eharmony because the goal is to deliver the best matches to you — rather than require singles to do the searching themselves.

You’ll See Percentages for How Compatible You Two Are in Terms of Emotional Intimacy, Altruism & More

Perhaps the most impressive and important part of the profiles eharmony sends you is that the site shows you several percentages for how compatible you two are according to a list of traits. For example, you could be 90% compatible on an intellectual level, 91% compatible on how you view exclusivity, and 92% compatible on how you rate physical intimacy in a relationship (as you can see in the picture above).

If You Don’t Like Him or Her, You Can Pass. If You Do Like Him or Her, Start Communicating Via Icebreakers & More Questions

Once you decide whether you’re interested in the person or not, you can start communicating with them, or you can pass. eharmony’s flirting and messaging features are also unique. You can go ahead and send standard messages if you want, but, if you’re not sure how to kick off the conversation, the site offers pre-written icebreakers (e.g., “Your profile brought a smile to my face!”) and quick questions (e.g., “How often do you lose your temper?”).

Photo of eHarmony's Guided Communication

Guided Communication is eharmony’s messaging feature that includes pre-written icebreakers and more get-to-know-you questions, so it’s easy to have a conversation with your matches.

To get to know your matches even better, eharmony recommends using its patented Guided Communication process. First, you’ll exchange five multiple-choice questions from a list of 57 (e.g., “Do you enjoy debating the issues of the day with your partner?”). Next, you’ll exchange several must-haves and can’t-stands to see what you agree and disagree on. It’s easy, quick, fun, and insightful!

Note: You Can’t Search On Your Own

Another aspect about eharmony’s matching options is that you can’t search on your own. A lot of people enjoy that because they don’t have to do any work, and it relieves some of the pressure and stress. If that’s not your thing, you can always check out other sites, like Match and Zoosk, white allow you to browse through profiles and make filtered searches yourself.

eharmony: Taking the Work Off Your Shoulders

In-N-Out’s secret sauce will always be a favorite of mine, even if I can’t create a copycat recipe that’s 100% on point. I’ve accepted that there are some things in life that I’m just never going to know. That holds true for eharmony’s matching system as well. We don’t really need to know how it works — we just need to know that it does. We know for a fact eharmony works because the site is responsible for 4% of US marriages. You could be next!