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SPZ to SPLAT Converter Online

Convert SPZ compressed Gaussian Splatting files to SPLAT for maximum web viewer compatibility.

Last updated Mar 2026

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What You Should Know

Why Convert SPZ to SPLAT?

SPLAT is the format supported by the broadest range of existing web-based Gaussian Splatting viewers, including antimatter15, splat.io, and many Three.js-based implementations. If you have an SPZ file (from Scaniverse or a PLY-to-SPZ conversion) and need to share it with someone using a viewer that only accepts SPLAT, this converter bridges the gap. The output is a standard 32-byte-per-Gaussian SPLAT file compatible with all major web viewers.

Spherical Harmonics Trade-off

SPZ preserves spherical harmonics; SPLAT does not. When converting SPZ to SPLAT, the SH coefficients are discarded and only the DC component (base color) is retained per Gaussian. The resulting SPLAT file will look slightly flatter than the SPZ original when viewed with a renderer that supports SH. This is the same trade-off as PLY to SPLAT — view-dependent color effects are lost. For most real-world scenes, the difference is minor and may not be noticeable to the end viewer.

Comparing SPZ and SPLAT File Sizes

Converting SPZ to SPLAT typically increases file size by 4–6x. A 50 MB SPZ scene becomes approximately 200–300 MB in SPLAT (depending on Gaussian count and SH degree). This may seem counterintuitive — you are converting from a smaller format to a larger one. The reason is that SPLAT's fixed 32-byte layout is less efficient than SPZ's quantized gzip compression. If file size is important, consider keeping the SPZ and using a viewer that supports it natively, or convert to KSPLAT instead for smaller output.

SPZ vs SPLAT
FeatureSPZSPLAT
File SizeVery small — ~10% of equivalent PLYMedium — ~50% of equivalent PLY
Spherical HarmonicsYes — preserved through gzip compressionNo — base color only (SH stripped)
Web CompatibilityExcellent — Khronos/Niantic standardBroad — widely supported by web viewers
CompressionExcellent — quantization + gzip (~90% vs PLY)Moderate — fixed 32-byte layout
Progressive LoadingNoNo
Typical UseWeb delivery, archiving, Scaniverse, long-term storageWeb sharing, antimatter15 viewer, broad compatibility
Frequently Asked Questions
SPZ uses quantization and gzip compression to achieve 10x reduction vs. PLY. SPLAT uses a simpler, uncompressed 32-byte layout. Converting from SPZ to SPLAT decompresses the data and re-encodes it in the larger SPLAT layout. The SPLAT output will be approximately 5x larger than the SPZ input.
Yes. This converter produces a standard SPLAT file in the 32-byte-per-Gaussian format compatible with all antimatter15-spec viewers.
No. The total number of Gaussians is preserved exactly. Only the spherical harmonics coefficients are discarded — all positional and shape data is retained.
For editing with desktop tools, convert to PLY — it has the richest compatibility. SPLAT is for web viewing only and does not retain SH data. For desktop editing, PLY is always the better choice.
No. SPLAT format cannot store spherical harmonics by design. If you need SH preserved, keep the scene in SPZ format (which preserves full SH) or convert to PLY (the uncompressed reference format). SPLAT will always result in SH-free, base-color-only rendering.

Related Converters

PLY to SPLATPLY to KSPLATPLY to SPZSPLAT to PLYSPLAT to KSPLATSPLAT to SPZKSPLAT to PLYKSPLAT to SPLATKSPLAT to SPZSPZ to PLYSPZ to KSPLAT