How it works

PanoPosts adapts one wide or 360° photo to wherever you want to post it. For Facebook, Google Photos, Flickr, Kuula, and Google Street View it embeds GPano — a small block of metadata tags those viewers all read to recognize a JPEG as a panorama. For Instagram — which has no native panorama viewer — it slices the image into a swipeable carousel instead.

What Facebook checks

• • File is a JPEG.
• • EXIF contains a camera Make and Model.
• • XMP contains GPano tags with ProjectionType=equirectangular.
• • Aspect ratio is plausible for an equirectangular image (2:1 for full 360°).
• • File size and dimensions are within Facebook's upload limits.

The partial-pano trick

A wide stitched photo like 12135×1538 isn't a full sphere — but if you tell Facebook it's a cropped region of an imaginary full sphere, the swipe viewer kicks in. PanoPosts computes that imaginary sphere from the horizontal field of view you choose, then writes the crop offsets so the viewer pans across exactly the visible region.

Instagram carousel

Instagram has no native panorama viewer, so PanoPosts takes a different approach: it slices your wide image into 1:1 or 4:5 slides and packs them into a zip you upload as a multi-image post. Followers swipe through the slides like panning across the original. No GPano tags are written for Instagram — they'd be ignored anyway.

What is GPano?

GPano isn't a separate file format, app, or viewer — it's a Google-defined XMP metadata namespace. Think of it as a small block of tags PanoPosts embeds inside your JPEG's existing metadata that says "this is a panorama, here's its shape, and here's where the viewer should open."

All GPano tags share the same namespace URL — http://ns.google.com/photos/1.0/panorama/ — which is the lingua franca that Facebook, Google Photos, Flickr, Kuula, and Google Street View all read to decide whether to render a swipe/pan viewer instead of a flat image.

GPano XMP doesn't travel alone. PanoPosts also writes EXIF Make/Model (so platforms that demand a camera identity accept the file) and, for Street View exports, an EXIF GPS block (mandatory — Google rejects panoramas without coordinates). Together those three pieces — GPano XMP, EXIF identity, EXIF GPS — form the full "panorama signature" the glossary below catalogs.

Tag glossary

Every tag PanoPosts writes, grouped by purpose. Tag names are the literal attribute names you'd see in a metadata inspector like ExifTool.