Ultrasound guide
3D vs 4D Ultrasound: What Is the Difference?
The names sound like a ranking, but they describe the same technology used two ways. Here is what actually changes between them.
4.6average rating · 4,109 App Store
The Short Answer
A 3D ultrasound builds a still, surface-like image of your baby from reflected sound waves. A 4D ultrasound produces those same 3D images continuously, so you see movement in real time — the fourth dimension is time, not extra detail. For a single clear picture of the face, a 3D still and a frame paused from a 4D scan are effectively the same image quality.
“5D” and “HDlive” are marketing names for rendering and lighting techniques applied on top of the same underlying data. They can look warmer or more photo-like, but they do not capture more information than the 3D scan they are built from.
What Each One Is Good For
3D — the clearest single portrait
Best when you want one sharp still of the face to keep, print or work from.
4D — seeing behaviour
Shows yawning, stretching and hand movements as they happen. Lovely to watch, same still quality when paused.
5D / HDlive — rendering style
A lighting and colour treatment over 3D data. Changes the look, not the underlying detail.
2D — the clinical standard
What anatomy scans use. Not designed for facial portraits, but it is the view that matters medically.
What Actually Decides Image Quality
In practice, the difference between a stunning scan and a disappointing one is rarely 3D versus 4D. It is gestational age, the baby’s position, how much fluid sits in front of the face, and the skill of the sonographer.
That is why a 4D scan at 34 weeks can look far worse than a 3D scan at 28 weeks. If a clear face portrait is what you want, timing and position matter more than which label the clinic advertises.
Frequently Asked Questions
Is a 4D ultrasound better than 3D?+
Not for image detail. 4D shows the same 3D imaging in motion, so you see the baby moving. A paused 4D frame and a 3D still are comparable in quality.
What is a 5D ultrasound?+
5D and HDlive are marketing terms for advanced rendering and lighting applied to 3D ultrasound data. They change how the image is presented, not how much detail was captured.
Which should I book for a picture of the face?+
Either works. Timing matters far more — most clinics recommend roughly 26–30 weeks, and the baby needs to be facing the probe with fluid in front of the face.
Are 3D and 4D ultrasounds safe?+
They use the same ultrasound technology as standard 2D scans. Medical bodies advise that scans should be performed by trained professionals for medical reasons — ask your provider about non-medical keepsake scans.
Can I make my scan look like a real photo?+
Yes. FaceCast reconstructs the shapes in a 3D or 4D scan into a realistic baby portrait, free on iOS and Android.
Turn Any Scan Into a Portrait
3D or 4D — upload the scan you have and see a lifelike photo of your baby in seconds.
4.6average rating · 4,109 App Store