When people start planning an AI headshot, they usually obsess over the details you can see from across the room: the outfit, the background, the lighting. But the thing people actually remember about a headshot is your face — specifically, what your face is doing. A great headshot with the wrong expression reads as stiff or unapproachable, and a mediocre photo with the right expression can feel warm and trustworthy. So before you worry about your shirt color, it's worth figuring out one thing: should you smile?
The short answer is that there's no universal right answer. The better question is what impression you're trying to make, and who's going to be looking at the photo. Let's walk through the options.
What Your Expression Is Actually Communicating
Research on first impressions keeps landing on the same finding: people judge warmth and competence within a fraction of a second of seeing a face. Your expression is the main signal for both. A smile reads as warm, friendly, and approachable. A neutral or serious expression reads as competent, authoritative, and focused. The catch is that warmth and competence pull in different directions. You can't max out both with one expression — so you have to pick which one matters more for your situation.
Think about what you want someone to feel when they land on your profile. If you want them to think "this person looks easy to talk to," that's a smile. If you want them to think "this person looks like they know what they're doing," that's closer to a neutral look or a very slight smile.
The Smile Spectrum, From Big to None
There's a real difference between a full smile and a closed-lip smile, and most people don't think about it until they see the results side by side.
Big smile (teeth showing). This is the friendliest option. It works well if you're in a people-facing role — sales, teaching, childcare, hospitality, anything where clients pick you partly because you seem pleasant to be around. The risk is that a huge smile can read as less professional in formal contexts, and if the AI renders it even slightly off, you can end up looking like you're mid-laugh at a bad joke.
Closed-lip smile. This is the safest all-rounder. A subtle smile with your mouth closed keeps you approachable without giving up any authority. It's the expression you see on most LinkedIn photos and most corporate team pages, and it translates especially well in AI headshots because there's less for the AI to get wrong around your teeth and mouth.
Neutral and serious. No smile, relaxed face. This reads as confident and no-nonsense. It's common in law, finance, executive roles, and any industry where the photo is meant to project authority rather than friendliness. The danger zone: a neutral expression in a flat photo just looks like you're miserable. If you go this route, your eyes and your posture have to carry the photo.
Match the Expression to Your Field
Your industry is a decent shortcut for choosing. For client-facing and creative roles — real estate, recruiting, therapy, design, fitness — a visible smile usually pays off because clients are choosing you partly on likeability. For advisory and authority roles — law, accounting, consulting, executive positions — a slight smile or neutral expression tends to fit better. And for fields like medicine, there's a middle ground: warm but calm, a closed-lip smile rather than a big one.
It also helps to look at what the top people in your field are doing. Pull up the team pages of three or four companies you respect in your industry and count how many people are smiling. That's a free market research exercise, and it tells you the norm you're competing against.
How AI Headshots Handle Expressions
One thing to know before you generate: an AI headshot generator tends to reproduce the expression from your source photos. Upload mostly neutral selfies and you'll get neutral headshots. Want a smiling headshot? Upload photos where you're genuinely smiling — and ideally pick a source photo with the exact smile intensity you want, because "smile harder" isn't something the AI can dial up reliably.
A couple of practical notes. If you want a teeth-showing smile, make sure at least one of your source photos actually has that smile; otherwise the AI will guess, and its guesses about teeth can look uncanny. Also, avoid a forced smile in your source photos. A real smile reaches your eyes — photographers call it a Duchenne smile — and the AI picks up on those subtle eye cues. A photo where you're smiling politely but your eyes are flat will produce a headshot that feels off even if you can't put your finger on why.
How to Decide (and Test)
If you're torn, don't pick — test. Generate one version with a closed-lip smile and one with a neutral expression, then compare them side by side. Show both to a friend or two and ask what impression each one gives. You'll usually get an answer within ten seconds, and it's almost always the same answer.
One more tip: think about where the photo lives. A headshot for your email signature can be warmer than the one on your LinkedIn. A headshot on a professional bio page can be more formal than the one on your dating profile. There's no rule saying you have to use the same expression everywhere — and since generating a new one takes minutes, you don't have to.
Bottom Line
Your expression is the single highest-leverage decision in your headshot. A smile buys you approachability; a neutral face buys you authority; and a closed-lip smile buys you a bit of both. Match the expression to the impression you want to make, keep your source photos genuine, and don't be afraid to generate two versions and let people vote. Get that part right, and the rest of your AI headshot just needs to stay out of the way.