What Are LAS and LAZ Files? A Point Cloud Format Guide
The difference between LAS and LAZ, what a point cloud file actually contains, and how to view LAS/LAZ in the browser with no installation.
2026-07-17 · 2 min read
LiDAR scanners and photogrammetry software produce point clouds — millions of three-dimensional points. The de-facto standard for this data is the LAS format and its compressed sibling LAZ. This guide explains both formats, what they carry, and how they are viewed in CartaX.
The LAS format
LAS (LASer file format) is an open binary format standardized by ASPRS. Every point carries at least an X-Y-Z coordinate; most files also include:
- Intensity: laser return strength
- Classification: ASPRS class codes such as ground, vegetation, building
- Color (RGB): in photogrammetric or camera-fused outputs
- GPS time and return number: for multi-return LiDAR analysis
The file header stores the coordinate reference system (CRS) and extent — CartaX georeferences your data from this information.
LAZ: compressed LAS
LAZ is the lossless compressed form of LAS; it is typically 75-90% smaller with exactly the same content. For moving data from a field disk to the cloud, LAZ is almost always the right choice: the same point cloud, a fraction of the upload time.
Practical rule: if you have LAS and upload time matters, converting to LAZ first (e.g. via your production software's export option) shortens the total time significantly.
Viewing LAS/LAZ in CartaX
Upload your LAS or LAZ file directly to CartaX; it is converted in the cloud to a browser-friendly octree structure and opens fluidly in the map scene. No installation, plugins or a powerful workstation needed — viewing works in any device's browser.
The conversion limit is 5 GB / 150 million points per file (all limits: Supported Formats). The viewer ships with class and elevation filters, cross-sections and measurement tools.
Larger datasets: the ready-octree path
For projects beyond 150 million points, convert the data to an octree on your desktop and upload it as a "ready octree"; this path uses no processing tokens and is only subject to your storage quota. CartaX Studio does that conversion on your own machine in a single step.
Summary
| Question | Answer |
|---|---|
| LAS or LAZ? | Same data; LAZ is 75-90% smaller — use LAZ for uploads |
| What's the limit? | 5 GB / 150M points for conversion; storage quota for ready octrees |
| Do I need to install anything? | No — viewing is entirely in the browser |
| Are colors/classes preserved? | Yes; class and elevation filters are available in the viewer |