Gaussian Splat File Formats: .ply, .splat, .spz & .sog
Guide · 2026-06-11 · 7 min read · by SplatMart Team
A practical guide to Gaussian splat file formats — what .ply, .splat, .spz and .sog are, how they differ in size and support, and how to convert between them.
Gaussian splats are saved in a handful of file formats, and the one you choose affects file size, loading speed, and which tools can open it. The main formats are .ply, .splat, .spz, and .sog. Here's what each is, how they compare, and how to convert between them.
.ply — the universal source format
PLY (Polygon File Format) is the most common way splats are stored, especially straight out of training. It holds every Gaussian's full data (position, scale, rotation, colour with view-dependent terms, opacity) in an uncompressed form. That makes it the most compatible and editable format — but also the largest, often hundreds of megabytes.
.splat — the lightweight web format
The .splat format strips a splat down to the essentials and packs it efficiently, so it loads faster — particularly in web viewers. It's a popular delivery format when you want a splat to open quickly online. The trade-off is that it may drop some higher-order colour detail compared to a full .ply.
.spz and .sog — modern compressed formats
- .spz — Niantic's open compressed splat format (born from Scaniverse), shrinking files by roughly 10x while keeping quality high. Well supported in mobile and web pipelines.
- .sog — the Self-Organizing Gaussians format adopted by PlayCanvas/SuperSplat as its web standard, compressing scenes up to ~20x. A 16MB product splat becomes ~4MB — the difference between a sluggish page and an instant one.
These formats exist because raw .ply files are simply too big to stream comfortably. Compression interacts with spherical harmonics too — the view-dependent colour data that makes reflections shift realistically. Higher SH detail means bigger files, which is why some web exports trim it; if accurate reflections matter (car paint, glass), check what the compressed version keeps.
Which format should you use?
- Keep a .ply as your master/source — it's the most editable and compatible.
- Deliver on the web with .splat, .spz, or .sog for fast loading.
- For a game engine, use whatever your splat plugin supports best (often .ply or .splat).
How to convert between splat formats
Converting (for example, .ply to .splat) is common and well-supported. Many capture apps export multiple formats directly, web viewers often include a converter, and command-line tools exist for batch conversion. The usual workflow is: train or capture to .ply, then convert to a compressed delivery format for sharing.
On SplatMart, listings note the file format so you know exactly what you're getting and that it will work in your pipeline. Browse the marketplace to see available splats and formats.
Frequently asked questions
What file format is a Gaussian splat?
Most commonly .ply (uncompressed, fully compatible) or .splat (lightweight, web-friendly). Newer compressed formats include .spz and .sog, which are much smaller and good for streaming.
How do I convert a .ply to a .splat?
Many capture apps and web viewers can export or convert directly, and command-line tools exist for batch jobs. The common flow is to keep the .ply as the source and convert to .splat (or .spz/.sog) for delivery.
Why are .ply splat files so large?
Because .ply stores every Gaussian's full data uncompressed, including view-dependent colour terms. Compressed formats like .spz and .sog reduce size dramatically for sharing.
Which splat format loads fastest on the web?
Compressed formats (.spz, .sog) and the lightweight .splat load faster than a raw .ply, which is why they're preferred for web viewers and streaming.