What Is Parallel-Eye 3D?
The side-by-side format explained without jargon.
Parallel-eye 3D — also called side-by-side or SBS 3D — is the simplest way to store and display 3D images and video: two slightly different views of the same scene, placed next to each other.
The basic idea: two eyes, two images
Your brain creates depth because your two eyes see the world from two positions about 6.5 cm apart. Parallel-eye 3D reproduces exactly that: the left half of the frame is the view from the left eye's position, and the right half is the view from the right eye's position. When the two halves reach the correct eyes, the brain merges them into a single scene with depth — the same mechanism that makes real-world vision feel three-dimensional.
How to view it without glasses
No hardware is needed. Look at the image and gently relax your eye muscles, as if you were staring at something far away, so your lines of sight move past the screen. The two inner images slide together and lock into one 3D picture. Tips that help:
- Start with a small image — smaller images are much easier to fuse.
- Hold a phone close to your face for a few tries until it 'clicks'.
- Look at the space between the two halves, not directly at either one.
Most people get it within a few minutes of practice. If you'd rather not, play the file in a VR headset or 3D TV instead — those devices handle the eye separation for you.
Parallel-eye vs. cross-eye vs. anaglyph vs. VR
- Parallel-eye (SBS): left view left, right view right. Full color, no glasses, native to VR and 3D displays. Easiest for most people to fuse.
- Cross-eye: the halves are swapped so you cross your eyes to fuse them. Works on any screen but causes eye strain for beginners.
- Anaglyph (red-cyan): two colors overlaid, needs colored glasses, and color accuracy suffers. No modern display uses it as its native format.
- VR / headset: the display shows a separate image to each eye with a lens. SBS video plays inside most VR players, effectively 'unpacking' the two halves.
Where side-by-side 3D is used
SBS is the de facto standard for 3D video. VR video players (Skybox, DeoVR, and many others) play SBS files directly; 3D Blu-ray and 3D TVs use side-by-side or top-bottom framing; and the huge 3D communities on Reddit and Flickr share SBS images and clips every day. If a file is described as 'parallel', 'SBS' or 'side-by-side', it all means the same thing.
Try converting your own video →
Convert any 2D clip into parallel-eye 3D in your browser — no upload, no install.
Frequently asked questions
Do I need glasses to see parallel-eye 3D?
No. Parallel-eye 3D is viewed by relaxing your eyes so the two side-by-side images merge. Some people find it easier with a phone held close to the face.
Why do I see four images when I look at a parallel-eye picture?
You are seeing double because your eyes are converging on the screen instead of looking 'through' it. Relax your gaze until the inner two images overlap into one 3D picture.
Is parallel-eye the same as side-by-side (SBS)?
Yes. Side-by-side is the container format; parallel-eye is the viewing method. In SBS files the left view is on the left and the right view is on the right, which matches parallel-eye viewing.
Can anyone learn to view parallel-eye 3D?
Most people can with a little practice. Start with a small image, place it at arm's length, and slowly relax your eyes. After a few attempts the depth 'clicks'.
What devices play side-by-side 3D video?
VR headsets (most 3D video players), 3D TVs, 3D projectors and many mobile 3D viewers all accept SBS video. On a regular phone you can still cross-view or use a foldable viewer.