What kind of photo does a panorama viewer need?

An equirectangular 360 photo: one picture twice as wide as it is tall, covering 360 degrees across and 180 degrees from straight up to straight down. It is the format 360 cameras save or export. JPEG, PNG and WebP open in every current browser, and the viewer prints the photo's size, megapixels and shape as soon as it opens.

Why does my phone panorama look bent in the viewer?

A panorama made by sweeping a phone across a scene is a wide strip that covers much less than the whole sphere, so it is not 2:1. The viewer still opens it, stretched around the sphere, and says under the view that the picture is not 2:1 and will look bent. Only a full 360 by 180 photo lines up without distortion.

Is my photo uploaded anywhere?

No. The browser decodes the file in this tab and your graphics hardware draws it; nothing is sent to a server. The only thing kept between visits is the projection you last used and whether the horizon guide was on, stored in this browser. The photo itself is never stored.

How do I fix a tilted horizon in a 360 photo?

Press Level horizon. A teal line appears along the true horizon, and two controls appear: tilt raises or lowers the photo at its front (yaw 0), and roll turns it clockwise or anticlockwise there. Nudge either by half a degree or type a value up to 45 degrees either way until the photo's horizon sits on the line. The correction changes the view and the saved PNG, never your original file.

What does the stereographic view do?

Rectilinear keeps straight lines straight but stretches everything near the edges once the view gets wide, so it stops at 100 degrees across. Stereographic keeps shapes near the edges in proportion and zooms out to 240 degrees across. Look straight down with it zoomed out and the ground curls into the little planet look.

How large a photo can it open?

It is built for photos up to 32 megapixels, such as 8000 x 4000. A photo wider than the graphics card's texture limit is cut into tiles that each fit, each keeping the photo's own pixels, so nothing is scaled down. If the device runs out of graphics memory, or the browser decodes the file smaller than its header says, the page says so and suggests opening a resized copy rather than showing a blurred one.

What size is the saved PNG?

It is the view exactly as drawn by your graphics card: normally the viewer's size on your screen times the display's pixel density, up to twice, or smaller when the browser gives the viewer a smaller drawing surface than it asks for. The readout prints that exact size before you save, and the saved message repeats it. In full screen the PNG is larger, and the horizon guide line is left out of the saved picture.

Panorama Viewer

Open an equirectangular 360 photo, the 2:1 kind that 360 cameras save or export, and look around it as if you were standing where it was taken. Drag or use the arrow keys to turn, zoom with the wheel, a pinch or the + and - keys, and switch between a rectilinear view, where straight lines stay straight, and a stereographic one that keeps shapes in proportion at wide angles and turns into a little planet when you look straight down zoomed out. If the camera was not level, tilt or roll the photo against a guide line drawn along the true horizon. Save PNG writes the current view, without the guide line, at the pixel size the viewer draws on your screen, which the readout prints. Two things set it apart: the photo is opened in this tab and never uploaded, and a photo wider than your graphics card's texture limit is split into tiles at its own resolution rather than quietly shrunk. A device that cannot hold a photo says so instead of showing it blurred. Yaw, pitch and field of view are numbers you can read and type, and the page prints the photo pixel under the centre of the view.

Open a 360 photo

· or drop one on the stage · or

Never uploadedNo accountDrawn by your graphics cardFull resolution

Image: none yet

Yaw: °

Pitch: °

Field of view: ° across

PNG: none yet

Straight lines stay straight, the way a normal camera lens draws them. Drag or use the arrow keys to look around (shift for 1° steps); the wheel, a pinch, the + and - keys or the zoom buttons set the field of view from 30° to 100° across. Yaw wraps past 180° with no seam, pitch stops at 90° up and 90° down, and 0 or Home faces the front.

View centrethe photo pixel under the middle of the view
open a photo first
Yaw past 180°180°, then 10° more to the right
-170°, the two image edges meet with no seam
Pitch past the pole85°, then 20° more up
stops at 90°, the view never flips
Checkerboard fixture4096 x 2048, 512 px squares, yaw 0°, pitch 0°
view centre on image point (2048, 1024), where four squares meet

Accuracy. Every image is read as an equirectangular 360 photo, 360 degrees across and 180 top to bottom, so a picture made another way still opens but looks bent. Nothing is stitched or measured, and the photo's location is never read. Photos up to 32 megapixels are kept at full resolution on your device's graphics hardware and never uploaded; when a device cannot hold one, the page says so instead of showing it blurred.

Common questions

What kind of photo does a panorama viewer need?: An equirectangular 360 photo: one picture twice as wide as it is tall, covering 360 degrees across and 180 degrees from straight up to straight down. It is the format 360 cameras save or export. JPEG, PNG and WebP open in every current browser, and the viewer prints the photo's size, megapixels and shape as soon as it opens.
Why does my phone panorama look bent in the viewer?: A panorama made by sweeping a phone across a scene is a wide strip that covers much less than the whole sphere, so it is not 2:1. The viewer still opens it, stretched around the sphere, and says under the view that the picture is not 2:1 and will look bent. Only a full 360 by 180 photo lines up without distortion.
Is my photo uploaded anywhere?: No. The browser decodes the file in this tab and your graphics hardware draws it; nothing is sent to a server. The only thing kept between visits is the projection you last used and whether the horizon guide was on, stored in this browser. The photo itself is never stored.
How do I fix a tilted horizon in a 360 photo?: Press Level horizon. A teal line appears along the true horizon, and two controls appear: tilt raises or lowers the photo at its front (yaw 0), and roll turns it clockwise or anticlockwise there. Nudge either by half a degree or type a value up to 45 degrees either way until the photo's horizon sits on the line. The correction changes the view and the saved PNG, never your original file.
What does the stereographic view do?: Rectilinear keeps straight lines straight but stretches everything near the edges once the view gets wide, so it stops at 100 degrees across. Stereographic keeps shapes near the edges in proportion and zooms out to 240 degrees across. Look straight down with it zoomed out and the ground curls into the little planet look.
How large a photo can it open?: It is built for photos up to 32 megapixels, such as 8000 x 4000. A photo wider than the graphics card's texture limit is cut into tiles that each fit, each keeping the photo's own pixels, so nothing is scaled down. If the device runs out of graphics memory, or the browser decodes the file smaller than its header says, the page says so and suggests opening a resized copy rather than showing a blurred one.
What size is the saved PNG?: It is the view exactly as drawn by your graphics card: normally the viewer's size on your screen times the display's pixel density, up to twice, or smaller when the browser gives the viewer a smaller drawing surface than it asks for. The readout prints that exact size before you save, and the saved message repeats it. In full screen the PNG is larger, and the horizon guide line is left out of the saved picture.

Every image is read as an equirectangular 360 photo, 360 degrees across and 180 top to bottom, so a picture made another way still opens but looks bent. Nothing is stitched or measured, and the photo's location is never read. Photos up to 32 megapixels are kept at full resolution on your device's graphics hardware and never uploaded; when a device cannot hold one, the page says so instead of showing it blurred.