How to do it, step by step
- Fix the white balance on the whole photo first Teeth are near-neutral, so they take a colour cast more visibly than skin. Correcting an orange cast often whitens them completely for free.
- Set the exposure on the face before touching the teeth If the face is underexposed the teeth will look dull, and lifting them alone will put them out of proportion with everything else.
- Mask the teeth only, zoomed in Use a brush in Lightroom or Snapseed's Brush tool and zoom in far enough to keep off the lips and gums. Spill onto the gums is the loudest giveaway there is.
- Drop saturation before you add any brightness Saturation down 15 to 25 points. Stop and look, because this is usually the entire edit and the yellow was what you were reacting to.
- Add at most a third of a stop of brightness Exposure up 0.15 to 0.30 and no further. Wanting more than that means the face is underexposed, not the teeth.
- Check against the eyes and any white in the frame Teeth must stay darker than the whites of the eyes and clearly darker than a white shirt or wall. Check it at full screen, not at phone size.
Teeth are not white, and that is the whole problem
Healthy enamel is translucent and sits over dentine, which is yellow. That is anatomy, not neglect. Put a sheet of copier paper next to almost anybody's smile and the paper wins comfortably, which is the first thing to know before you drag a slider.
Teeth also are not one colour. They are brightest on the flat front surface of the two upper incisors, slightly darker and more saturated at the canines, darker again towards the back of the mouth, and there is normally a band of extra colour near the gum line and a slightly translucent, faintly grey edge at the biting edge of the front teeth. That variation is what a viewer reads as teeth.
Almost every bad whitening job destroys the variation rather than the colour. A whitening brush set high flattens the whole mouth to one even bright value, and the result looks less like clean teeth and more like a single white shape with divisions drawn on it. The colour was never really the problem. The gradient was doing the work.
Desaturate and lift, do not whiten
The correct move is small and it is mostly about saturation.
Take yellow out before you add brightness. On a local adjustment over the teeth, drop saturation by 15 to 25 and stop there for a moment. Nine times out of ten that is the whole edit, because what you were reacting to was the yellow, not the darkness.
Then lift very slightly. Exposure up 0.15 to 0.30 of a stop, no more. If you find yourself wanting more than that, the face is probably underexposed and you should fix the exposure on the face instead, which will lift the teeth with it and keep everything in proportion.
Keep the adjustment inside the teeth. The most common technical error is letting the brush spill onto the lips and gums, which desaturates them too. Pale, grey-pink gums are the single loudest giveaway of an app-whitened smile, louder than the teeth themselves.
Do it last. White balance, exposure and any colour grading all shift the apparent shade of teeth. Whiten before those and you will be correcting the correction.
Where the tool lives in each app
| App | What to use | What to set | Failure mode |
|---|---|---|---|
| Lightroom, free tier | Brush mask over the teeth | Saturation minus 15 to minus 25, Exposure plus 0.15 to 0.30 | None inherent. The brush needs care around the lip edge |
| Snapseed | Brush tool: Saturation brush, then Dodge and Burn | Saturation minus 5, one light dodge pass | The brush is coarse at low zoom, so zoom right in before you start |
| Snapseed | Selective control point on the mouth | Saturation down a little | Selective spreads by tonal similarity, so it leaks onto lips and skin |
| Apple Photos | Nothing suitable | Global only | No local adjustments, so any change hits every yellow in the frame |
| Facetune | The Whiten tool | Well below the default | Fast and well masked, but it pushes towards pure white and brightens gums along with teeth |
Facetune's whitening is worth naming honestly on both counts. The masking is better than anything free, so it stays inside the teeth without you doing careful work. And it is calibrated for a look that is past the line in a single pass, so if you use it, cut the strength to roughly a third of where it lands by default and check it at full size.
Where the line is, exactly
Four checks. If a photo passes all four, nobody will know anything was done.
1. Teeth stay darker than the whites of the eyes. In a face lit normally, the sclera is the brightest near-neutral thing there is. The moment teeth out-brighten eyes, the smile reads as inserted.
2. Teeth stay darker than white fabric in the same frame. If there is a white shirt, a white wall or a paper cup in shot, it is a free reference. Teeth should be clearly below it.
3. The gradient survives. Front incisors brightest, canines a little darker and warmer, back teeth darker again, a slightly deeper band at the gum line. If the mouth has become one flat value, undo and start over with less.
4. Gums are still pink. Desaturated gums are the tell that people spot without knowing why. Check the gum line at full size.
A fifth, more useful than all of them: look at the photo at full screen rather than phone size. Whitening that looked subtle on a phone is regularly two or three times too strong when it lands on a laptop, and a profile picture will be opened on a laptop by somebody.
Often the teeth are fine and the photo is orange
Before reaching for a whitening tool at all, check whether the whole photo has a colour cast, because teeth show one more visibly than skin does. Skin is already warm, so a warm cast hides in it. Teeth are close to neutral, so they take a cast directly, which is why the same smile looks fine in a daylight photo and yellow in a kitchen one.
Indoor bulbs run around 2700 kelvin against roughly 5500 for daylight, and automatic white balance often splits the difference and leaves warmth on the frame. Correct that and the teeth whiten for free, along with everything else that should be neutral. The orange skin tone guide covers the correction in detail.
Two smaller causes worth ruling out. A yellow or cream wall behind the camera bounces its colour onto everything facing it. And lip colour changes the apparent shade of teeth more than a whitening slider does, because the eye judges the teeth against whatever is next to them: a blue-based red makes teeth read cooler and brighter, and an orange or coral tone makes exactly the same teeth read yellower.
What reads before the shade does
Tooth shade is a long way down the list of things a viewer registers in a smile, which is worth remembering before spending ten minutes on it.
What actually reads is the eyes. A smile that reaches the eyes, with the cheeks lifted and the outer corners creased, is read as genuine within a fraction of a second; a mouth-only smile is read as posed just as fast, however bright the teeth. The reliable way to get one is timing rather than instruction. A real laugh peaks with the eyes closed and the mouth wide, and the usable frame is about two seconds into the decay, when the eyes have opened and the mouth has softened. Shoot through it rather than at it.
After that it is exposure on the face, then whether the lips are relaxed, then the shade. Fix the first two and the third stops bothering you.
Ours, so discount it: ShutterAI's Glow retouch has no whitening slider and never will, because there is no version of that control that most people use well. It evens skin tone, softens a temporary mark and leaves texture and face shape alone. Not released yet, coming to iPhone this fall, free to start, with a waitlist on the homepage.
Questions people ask
How do you whiten teeth in photos?
Mask the teeth only, drop saturation by 15 to 25 points, then lift exposure by no more than a third of a stop. Do it after white balance and exposure are set. Pushing brightness towards white without removing yellow first is what produces the fake look.
How white is too white for teeth in a photo?
Once teeth are brighter than the whites of the eyes, or as bright as white fabric in the same frame, it has gone too far. The other giveaways are a mouth that has become one flat even value with no gradient towards the back teeth, and gums that have lost their pink.
Can you whiten teeth in Apple Photos?
Not properly. Apple Photos has no local adjustments on iPhone, so any saturation or brightness change lands on the whole frame and takes every other yellow with it. Use Snapseed's Brush tool, which is free, or Lightroom's free tier.
Why do my teeth look yellow in photos but not in the mirror?
Usually a colour cast rather than the teeth. Indoor bulbs run around 2700 kelvin and automatic white balance often leaves warmth in the frame. Teeth are close to neutral so they show that warmth directly, while your already-warm skin hides it. Correct the white balance first.
Does Facetune whiten teeth well?
The masking is better than anything free, so it stays inside the teeth without careful work. The calibration is the problem: at its default strength it pushes towards pure white and lightens the gums too, which is past the line in one pass. Cut it to roughly a third and check at full size.