GRASS
Free, open-source GIS engine for raster, vector and time-series geospatial analysis.
Updated · AppBreakup editorial · Windows, macOS, Linux
Is GRASS free?
Yes, free and open source
- License:
- GNU GPL v2 or later
Checked on GRASS's site Nov 8, 2026
Switch from GRASS to
All 2
QGISOpen source
ArcGIS ProPaid
- Verified facts
- 5 of 5
- Alternatives ranked
- 2
- Approved reviews
- 0
- Visits sent from here
- 0
About GRASS
GRASS (Geographic Resources Analysis Support System) is one of the oldest GIS packages still in active development: the US Army Corps of Engineers started it in 1982, and today an international volunteer team maintains it under the Open Source Geospatial Foundation. It is built for analysis rather than map layout. It has hundreds of modules for terrain and hydrology modelling, land-cover and imagery processing, network analysis and vector topology, plus a temporal framework for working with long series of rasters. You can drive it from its own desktop GUI, from the command line, from Python, or through QGIS, which exposes many GRASS tools in its Processing toolbox. Researchers, environmental agencies and students are the typical users; people who mainly want to style and print maps usually find QGIS friendlier. GRASS is free under the GNU GPL and runs on Windows, macOS and Linux, with Docker images and conda-forge packages for servers and notebooks. Paid help is available from third-party commercial support providers listed on the project site.
Best for: Researchers and analysts who need heavy raster, terrain or hydrology processing and can script it.
Pros and cons
What works
- Very deep set of raster, vector and imagery analysis modules
- Python API and command line make large batch jobs repeatable
- Built-in temporal framework for time-series rasters
- Free under the GPL, with decades of documentation and teaching material
Why people leave
- Steeper learning curve than QGIS, with its own project and region concepts
- Weak at cartography and print layouts compared with QGIS or ArcGIS Pro
- The desktop GUI looks dated next to commercial GIS tools
GRASS vs QGIS and ArcGIS Pro
From each app's listing and the prices verified on its own site. A dash means we haven't verified it yet.
| Attribute | GRASS | QGIS | ArcGIS Pro |
|---|---|---|---|
| Pricing | Open source | Open source | Paid |
| Verified price | — | — | — |
| Free plan | Free app | Free app | No |
| Open source | Yes | Yes | No |
| Self-hostable | No | No | No |
| Platforms | Windows, macOS, Linux | Windows, macOS, Linux | Windows |
Top GRASS alternatives
See all 2- 1QGIS68.8
Friendlier desktop GIS with strong map styling and layouts; it can still call GRASS modules from its toolbox.
- 2ArcGIS Pro64.8
Commercial industry standard with polished cartography, vendor support and a huge ready-made toolset.
Why people left GRASS
In reviewers' own words, from reviews of the apps they moved to. These are their opinions, not ours.
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Reviews
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GRASS: common questions
What is GRASS?
GRASS: Free, open-source GIS engine for raster, vector and time-series geospatial analysis. Best for researchers and analysts who need heavy raster, terrain or hydrology processing and can script it. Available for Windows, macOS and Linux.
Is GRASS free?
Yes. GRASS is free, open-source software.
Is GRASS open source?
Yes. The source code is on GitHub at OSGeo/grass.
What platforms does GRASS run on?
GRASS is available for Windows, macOS and Linux.
What are the best alternatives to GRASS?
The highest-ranked GRASS alternatives right now are QGIS and ArcGIS Pro. See the full ranked list for pricing, platforms and verified facts.
GRASS vs QGIS: what's the difference?
Both GRASS and QGIS are free and open source. Both run on Windows, macOS and Linux.