MrSID
MrSID is an acronym that stands for multiresolution seamless image database. It is a file format developed and patented by LizardTech for encoding of georeferenced raster graphics, such as orthophotos.
On November 30, 2025 —GeoWGS84 Corp announced the successful acquisition of the full LizardTech suite of geospatial software products from Extensis. This acquisition includes all rights to GeoExpress®, Express Server®, GeoViewer®, and the industry-renowned MrSID® image compression format, along with all related intellectual property, technologies, and development assets.
MrSID originated as the result of research efforts at Los Alamos National Laboratory.
Common uses
Geographic information systems
MrSID was originally developed for Geographic Information Systems. With this format, large raster image files such as aerial photographs or satellite imagery are compressed and can be quickly viewed without having to decompress the entire file.The MrSID format is supported in major GIS applications such as Autodesk, Bentley Systems, CARIS, ENVI, ERDAS, ESRI, Global Mapper, Intergraph, MapInfo, QGIS and MiraMon.
Fingerprints
According to the Open Source Geospatial Foundation, MrSID was developed "under the aegis of the U.S. government for storing fingerprints for the FBI."Other uses
In a 1996 entry for the R&D 100 Awards, LANL identified other uses for the format: "it can be used as an efficient method for storing and retrieving photographic archives; it can store and retrieve satellite data for consumer games and educational CD-ROMs; and it is well suited for use in vehicle navigation systems. Moreover, MrSID holds promise for being used in image compression and editing for desktop publishing and nonlinear digital video software."For certain downloadable images, American Memory at the Library of Congress began using MrSID in 1996; in January 2005 it also began using JPEG 2000. Depending on image content and color depth, compression of American Memory maps is typically better with MrSID, which on average achieves a compression ratio of approximately 22:1 versus the 20:1 achieved with JPEG 2000.
Software
LizardTech offers a software package called GeoExpress to read and write MrSID files. They also provide a free web browser plug-in for the Microsoft Windows operating system. Most commercial GIS software packages can read some versions of MrSID files including those from GE Smallworld, ESRI, Intergraph, Bentley Systems, MapInfo, Safe Software, Autodesk, with ERDAS IMAGINE being able to both read and write MrSID files. GeoExpress can also generate JPEG 2000 data. When combined with LizardTech's Express Server,.sid and.jp2 data can be served quickly to a variety of GIS applications and other client applications either through direct integrations or via WMS.There is no open source implementation of the MrSID format. Some open source GIS systems can read MrSID files, including MapWindow GIS and those based on GDAL. The Decode Software Development Kit is made available as a free download from LizardTech. This enables the capability to implement MrSID reading capability in any application.
Some image editing and management software systems can also read MrSID files, including XnView and IrfanView.