Online lying is a big factor in online dating, so let’s take an honest look at it. I’m not talking about criminal intent, just everyday prevarication—almost everybody does it, and almost everybody gets away with it to some extent.

Lies lie on a spectrum

As all good Catholics know, there are sins of omission and sins of commission. Say you commit the sin of checking off the “single” box when setting up your online profile, although you are still technically married. But if you’ve been legally separated for nearly a year and are well on the way to a no-fault divorce, are you truly sinful? (Assuming you’re not a practicing Catholic.)

Say you omit information about your six personal bankruptcies, or conviction for domestic abuse, because the website asks no questions about credit score or criminal record when you set up your profile. But don’t these omitted facts constitute dealbreakers for most online daters?

So don’t assume committing a lie is worse than withholding information, in the eyes of your beholders.

Personal ethics aside, there are practical reasons to limit your online lying. In the Age of Google, mounds of personal information are available for free to a halfway-competent searcher, and even more gets served up to anyone willing to invest in an account at a snoop site.

But there are even better reasons for honesty. Lies about your appearance blow up when you show up for the first date. Lies about your personal status—a few dates down the line when the truth emerges—blow up your new friend’s trust. So why waste your time?

Practical truth-telling

Nevertheless, no one tells the whole truth no matter how honest online—at the very least, you’re withholding your full name. So let’s not be persnickety, let’s be practical and categorize online untruths at three levels: white lies (OK by me), lies that push boundaries (and can push away relationships), and liar liar pants on fire mendacity.

Photographs. This is one of the most commonsectors of falsehood, yet the most easily exposed. No matter how handsome the photographic prince, does anyone feel merciful when a frog walks in the door? You’re swimming upstream if you set outrageous expectations with your online image.

White Lie: Posting a professional headshot that softens your facial lineage while sharpening your jawline.

Boundary-Pusher: Posting a lot of flattering older photos, albeit with captions that say “Bridesmaid at Susie’s wedding a few years ago” or “I used to be such a Madonna fan” or “At my son’s Kindergarten graduation; he graduates Yale next spring.”

Pants on Fire: Posting the 15-years-old, 50-pounds-less full-body photo (subset: skimpy swimsuit), a common rookie mistake. No matter what you put on in the way of clothes and makeup for Date 1, it will be clear that photo is not who you are now, and this makes for a short Date 1. I’m not saying lose the 50, let alone the 15; I’m saying put it out there and find people who think you’re fine as you are.

Income. Granted, this is a bigger issue for men. Even in this day and age, making money is not generally considered part of the arsenal of attributes women must present—appearing too wealthy can intimidate some worthy men and draw others of the wrong sort. If you’re in the arts but not famous, the lower-middle income slot for your geography is acceptable. But looking poverty-stricken has its own problems.

White Lie: Making a salary in the $35,000-$50,000 range because you’re underpaid, but claiming you’re in the $50k-$75k or $75k-$100k range because you want to hit the middle-manager income zone in your metro area. (Except in New York City or San Francisco, where that’s a nanny pay grade.)

Boundary Pusher: Making lower-middle-class money but claiming a six-figure income because you want to attract a date who does. You’re setting yourself up to do quite a mysterious-lady dance while reeling him in—no hosting intimate dinners at your two-room condo. Unless, of course, it’s a Tribeca loft.

Pants on Fire: Making no money but claiming a six-figure income because you lost your mistress gig and you need a new source of support. Something like this happened to a man I know. The relationship went on longer than it should have because each person thought the other had more money than he/she actually did, and it ended miserably for both.

Education. Statistics show there’s a correlation between income and education (until you get to the upper levels of the latter, because most Ph.D.s don’t make millions). Social experience shows there’s also a high correlation between snob appeal and two vectors of education: advanced degrees like M.B.A., J.D. and M.D., and snooty schools like the Ivy League, the remaining shreds of the Seven Sisters, and brainy sports powerhouses like Stamford and Duke.

White Lie: Casually referring to your business studies at Wharton, and you did indeed take classes there while getting your undergraduate degree from UPenn. But you’re no Wharton M.B.A.

Boundary-Pusher: Casually referring to your days at Harvard, and you did indeed have about 40 of them in summer school.

Pants on Fire: Casually referring to “when I was at Princeton,” and indeed you were, working in the cafeteria.

Age. The age-gap disparity in romantic relationships is a persistent discriminatory hangover in women’s lives. Many men still like to date down in years. Women, in turn, tend to avoid crossing decade lines upward. This is why online daters may—and may have to—lie about their age.

White Lie: Saying you’re 49 when you’re 52. There’s a reason why retailers price detergent at $4.99 and landlords set the rent at $995—the magic of nines clouds our bargaining brains. Up to three years usually works if your functionality beats your chronology, but you must correct the record long before things get serious with your new friend. I can testify firsthand about receiving frequent absolution from this little sin.

Boundary-Pusher: Saying you’re 49 when you’re 56. Even if all your friends say you look it, when the time comes to share your passport scan with your 52-year-old boyfriend as he assembles paperwork for that cruise he’s taking you on, you’re going to have a lot of ‘splainin’ to do. Especially if you don’t otherwise partake in Lucy-like giddiness.

Pants on Fire: Anything over nine years, no matter how great you look. Because you don’t look so great that anyone, male or female, will not wonder about your self-image and sanity when they learn the truth. Mind the gap.