Maps · head to head
GRASS GIS vs onX Maps
GRASS GIS
Maps
Long-running open source geospatial analysis engine for raster, vector and terrain processing
- From
- Free
- Rated
- -
onX Maps
Maps
Land ownership and offline navigation apps sold as separate subscriptions per activity: Hunt, Offroad, Backcountry
- From
- On request
- Rated
- -
The short version
- Only GRASS GIS has a free tier, so it costs nothing to try first.
- Each has a real cost: GRASS GIS the location and mapset data model requires importing data into a structured database with a fixed coordinate system before analysis, which is a real barrier for anyone used to opening files directly.; onX Maps hunt, Offroad and Backcountry are entirely separate subscriptions, so a user needing more than one activity pays for more than one product with no combined bundle discount.
- They diverge on capability: GRASS GIS covers Raster analysis, onX Maps covers Land ownership boundaries.
- Prices and features above were last checked on 1 September 2026.
Where they differ
Only the attributes on which GRASS GIS and onX Maps actually diverge.
Identical on both: user rating (Not yet rated), category (Maps).
What each one covers
Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.
Only in GRASS GIS
- Raster analysis
- Hydrological modelling
- Terrain analysis
- Vector topology
- Temporal framework
- Image processing
- Python API
- QGIS integration
Only in onX Maps
- Land ownership boundaries
- Offline maps
- Waypoint and track marking
- Elite tier private land data
- 3D terrain view
- Weather overlay
What people use each for
The jobs each tool is most often brought in to do.
GRASS GIS
- A hydrologist delineating watersheds and modelling flow accumulation over a large digital elevation modelnot onX Maps
- A research group building a reproducible time series analysis of satellite imagery that must be rerunnable years laternot onX Maps
- An environmental agency running viewshed and solar radiation analysis for planning assessments without buying commercial GIS seatsnot onX Maps
- A QGIS user who needs a specific processing algorithm that only exists in the GRASS toolboxnot onX Maps
onX Maps
- A hunter who needs to know exact private and public land boundaries before crossing onto a propertynot GRASS GIS
- An off-road driver planning a trail route with land ownership and access datanot GRASS GIS
- A backcountry skier or hiker wanting offline terrain maps without cell signalnot GRASS GIS
- Someone who does two or more of these activities and needs to budget for two or three separate subscriptionsnot GRASS GIS
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
GRASS GIS
- The location and mapset data model requires importing data into a structured database with a fixed coordinate system before analysis, which is a real barrier for anyone used to opening files directly.
- The native graphical interface is dated and inconsistent compared with QGIS or ArcGIS, so most users end up running GRASS through QGIS and never learn the tool they are actually depending on.
- There is no vendor, so contractual support, service levels and liability do not exist by default and must be arranged with an independent consultancy that may not cover your jurisdiction.
- Cartographic output and map layout are weak relative to the analysis capability, meaning a second tool is always needed to produce a publishable map.
- Module naming and argument conventions are idiosyncratic and long-standing, so scripts are durable but the learning curve is steep and transferable skills from other GIS packages help less than expected.
onX Maps
- Hunt, Offroad and Backcountry are entirely separate subscriptions, so a user needing more than one activity pays for more than one product with no combined bundle discount.
- Elite-tier pricing at roughly $99.99 a year per product is expensive if a buyer only occasionally needs the private land ownership data it adds.
- The apps are US and Canada focused, with more limited usefulness for international travel compared to a global mapping product.
- Land ownership data, while extensive, can lag real-world changes in property boundaries in fast-changing areas.
- It is not a general-purpose hiking or trail-review app in the way AllTrails or Gaia GPS are, so casual hikers without a land-boundary need may find the focus narrower than expected.
Pricing, plan by plan
GRASS GIS
Free- GRASS GISFree
- GNU GPL licence
- All modules included
- No user or seat limits
onX Maps
On request- onX Hunt Elite$99.99/year
- Nationwide private land ownership data
- Recent satellite imagery
- Offline maps
- onX Offroad Premium$34.99/year
- Trail and land ownership maps for off-road use
- Offline maps
- onX Offroad Elite$99.99/year
- Everything in Premium plus nationwide land ownership and recent imagery
- onX Backcountry$29.99/year
- Backcountry ski and hike focused maps
- Offline maps
- Avalanche and terrain data
Which should you pick?
Choose GRASS GIS if
- You need raster analysis.
- You want to start without paying.
- You work on Linux, Windows, macOS.
- You also want hydrological modelling.
Choose onX Maps if
- You need land ownership boundaries.
- You work on iOS, Android, Web.
- You also want offline maps.
Questions people ask
- Is GRASS GIS or onX Maps better?
- Neither clearly leads. GRASS GIS starts at Free and onX Maps at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, GRASS GIS or onX Maps?
- GRASS GIS has a free tier; the other does not. Paid plans start at Free for GRASS GIS and On request for onX Maps.
- Does GRASS GIS or onX Maps run on more platforms?
- GRASS GIS runs on Linux, Windows, macOS. onX Maps runs on iOS, Android, Web.
- Can I use GRASS GIS for free?
- Yes. GRASS GIS has a free tier, so you can try it without paying. onX Maps starts at On request.
- What is GRASS GIS best used for?
- GRASS GIS is most often used for a hydrologist delineating watersheds and modelling flow accumulation over a large digital elevation model, a research group building a reproducible time series analysis of satellite imagery that must be rerunnable years later, an environmental agency running viewshed and solar radiation analysis for planning assessments without buying commercial gis seats, a qgis user who needs a specific processing algorithm that only exists in the grass toolbox. Of those, a hydrologist delineating watersheds and modelling flow accumulation over a large digital elevation model and a research group building a reproducible time series analysis of satellite imagery that must be rerunnable years later are not what onX Maps is typically brought in for.
- What can GRASS GIS do that onX Maps cannot?
- GRASS GIS covers Raster analysis, Hydrological modelling, Terrain analysis, Vector topology. onX Maps covers Land ownership boundaries, Offline maps, Waypoint and track marking, Elite tier private land data.
Answered from the vendors’ own pages
GRASS GIS: Who maintains GRASS GIS?
An international volunteer and academic developer community under the Open Source Geospatial Foundation. It originated at the US Army Construction Engineering Research Laboratory in 1982.
onX Maps: Can I use one onX subscription for both hunting and off-roading?
No, onX Hunt, onX Offroad and onX Backcountry are separate apps with separate subscriptions.
GRASS GIS: Can I buy commercial support?
Not from a vendor. Independent consultancies in the OSGeo ecosystem offer paid support and development, and availability varies by region.
onX Maps: What does the Elite tier add?
Elite tiers add nationwide private land ownership data, more recent satellite imagery and partner discounts on top of the base Premium tier.
GRASS GIS: Do I need to use its interface?
No. Most people run GRASS algorithms through the QGIS processing toolbox or from Python.
onX Maps: Does onX work outside the US?
Coverage is strongest in the US and Canada; usefulness elsewhere is limited.
GRASS GIS: Is it suitable for production use?
Yes for analysis pipelines, and it is used by agencies and research institutions. Plan for community support rather than a service level agreement.
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