LASzip is our free open source product to quickly turn bulky LAS files into compact LAZ files without information loss. Terabytes of LAZ data are now available for free download from various agencies making LASzip, winner of the 2012 Geospatial World Forum Technology Innovation Award in LiDAR Processing and runner-up for innovative product at INTERGEO 2012, the de-facto standard for LiDAR compression.

LASzip squeezes the 5.3 Terabytes of LAS files that the National Land Survey of Finland serves on it’s public servers as part of an “open data” campaign into only 0.8 Terabytes of LAZ files.

Other success stories are OpenTopography that has been serving LAZ for two years and the comprehensive open LiDAR archive of the Department for Natural Resources of Minnesota that are exclusively provided in the LAZ format.

LASzip is a compression library that was developed by rapidlasso founder Martin Isenburg for compressing ASPRS LAS format data in LAStools. It has been provided as an LGPL-licensed stand-alone software library to allow other software that handle LAS data to read and write LASzip-compressed data. The BSD-licensed libLAS and our LASlib can take advantage of LASzip to read and write compressed data.

LASzip is completely lossless. It compresses bulky LAS files into compact LAZ files that are only 7-20 percent of the original size, accurately preserving every single bit. For example, compressing and decompressing the LAS file lidar.las with laszip.exe as shown below results in lidar_copy.las that is bit-identical to lidar.las. However, the small size of lidar.laz makes it much easier to store, copy, transmit, or archive large amounts of LIDAR.

  • laszip -i lidar.las -o lidar.laz
  • laszip -i lidar.laz -o lidar_copy.las

LASzip compression can be many times smaller and many times faster than generic compressors like bz2gzip, and rar because it knows what the different bytes in a LAS file represent. Another advantage of LASzip is that it allows you to treat compressed LAZ files just like standard LAS files. You can load them directly from compressed form into your application without needing to decompress them onto disk first. The availability of the LASzip DLL and two APIs, libLAS and LASlib, with LASzip capability makes it easy to add native LAZ support to your own software package.

Our free open-source LiDAR compressor LASzip has become the de-facto standard for compressed point clouds in the LiDAR industry.

This (may incomplete) list shows software and vendors which support LAZ format:

LASzip is included in our full download package and also available as sourcecode to be compiled in Windows, Linux or MacOS environments.

Find the specification of the LASzip format in this PDF.