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QGIS is a free, open-source desktop application for viewing, editing and analysing geospatial data. To use it, install it from qgis.org, set the project coordinate reference system (CRS), add your data layers through the Data Source Manager, style them, run analysis from the Processing Toolbox, and save the work as a project file. This guide walks through that sequence with the menu names and shortcuts given in the current QGIS documentation.
What QGIS is used for in research
The QGIS project describes the desktop application as a tool to “create, edit, visualise, analyse and publish geospatial information”, with support for “a multitude of data sources and formats” (QGIS project overview, checked 2026-10-29). The user manual describes it as a desktop application for visualising and configuring raster and vector data and exporting maps, and it can act as a front end for GRASS GIS (Getting Started). In research, that covers mapping study sites, overlaying survey or health data on boundaries, and working with gridded datasets such as the population rasters described in WorldPop open population data for research. For the discipline background, see what is geography and what is remote sensing.
QGIS Server, a separate component, publishes data as WMS, WMTS, WFS and WCS web services; this guide covers only the desktop application.
Install or access QGIS (official source only)
Download QGIS from qgis.org/download. The project lists installers and packages for Windows, macOS, Linux and BSD, plus containers. On Windows there is an online OSGeo4W installer and offline standalone installers; on macOS the installers are signed and notarised. Mobile data collection is handled by third-party apps (the download page names QField, Mergin Maps and IntraMaps Roam), not by the desktop program.
QGIS publishes two channels. The Long Term Release (LTR) is, in the project’s words, “intended for those who value stability over having the latest features”; the other channel carries the newest features. For a research project that must be re-run later, choose one channel at the start and record the exact version in your methods notes. The same page states that the software “is, and always will be, available free of charge if downloaded from QGIS.org” and that QGIS is open source under the GNU General Public License.
To quit, use Project ► Exit QGIS (shortcut Ctrl+Q).
Step-by-step: load data, style it and export a map
The steps below follow the official sample session in the Getting Started chapter, generalised to your own files.
- Know the screen. The menu bar holds Project, Edit, View, Layer, Settings, Plugins, Vector, Raster, Database, Web, Mesh, Processing and Help (plus a QGIS menu on macOS only). The Layers panel opens with Ctrl+1 and the Browser panel with Ctrl+2 (QGIS GUI).
- Set the project CRS. Click the Select projection button at the bottom right of the window. The Project Properties dialog opens on the CRS tab; type a code or name in the filter text area, select the row you want and press OK.
- Add a layer. Click the Open Data Source Manager icon (it opens in Browser mode), browse to the folder and double-click the file. You can also drag and drop the file onto the main window. If a file holds several layers, such as a GML file, the Select Items to Add dialog opens: choose the layer and press Add Layers. The layer appears in the Layers panel.
- Fix a missing CRS. If the Layers panel shows “Layer has no coordinate reference system set” beside a layer, click the icon and choose the correct CRS in the selector.
- Style the layer. Double-click the layer in the Layers panel to open its Properties dialog. On the Symbology tab choose a fill colour. On the Labels tab choose Single labels, pick the attribute field under Label with, and use the Buffer tab (Draw text buffer) to improve legibility. Press Apply, then OK.
- Add map furniture. Use View ► Decorations ► Scale Bar, tick Enable Scale Bar, and press Apply.
- Export the map. Choose Project ► Import/Export ► Export Map to Image…, press Save in the dialog, then select a location and format.
- Save the project. Use Project ► Save… (Ctrl+S). QGIS saves projects as
.qgzor.qgsfiles.
Running an analysis tool
Analysis tools live in the Processing Toolbox, which lists algorithms grouped by provider and has a Search box that filters by name or keyword. To run a tool, double-click its name; a dialog opens with a Parameters tab and a Log tab. Right-click a tool for Execute as Batch Process… (to repeat it over several inputs) or Add to Favorites. In a vector input, the iterator button runs the algorithm once per feature instead of once for the whole layer (Processing Toolbox).
Output and how to read it
The map canvas shows the layers in the order of the Layers panel. Algorithm results are added as new layers or written to a file you choose in the Parameters tab, and the Log tab records the run. Before you interpret any result, check the CRS. The QGIS manual warns that a wrong CRS “will place your layer in the wrong position on the Earth’s surface”, and that an inappropriate project CRS can make maps look distorted. Standard CRSs are identified as authority:code pairs, for example EPSG:4326 for WGS 84 latitude/longitude and EPSG:3857 for the web mapping standard (Working with Projections).
For reproducible work, note the QGIS version, the CRS, the source and date of each input layer, and the tools and parameters you ran. If you publish the project file alongside your data, follow the practices in computational reproducibility, and cite the software as described in how to cite software, code and R packages.
Troubleshooting
A layer appears in the wrong place, or not at all
Check the layer CRS first and compare it with the data provider’s metadata. If the CRS is missing, assign the right one; this changes how QGIS interprets the coordinates and does not alter the underlying file. For shapefiles, QGIS reads the CRS from the .prj file that shares the base name of the .shp file, so keep the two together.
QGIS keeps prompting for a CRS, or never does
The behaviour is set under Settings ► Options… ► CRS, in the CRS for layers group: leave the CRS unknown, prompt for a CRS, use the project CRS, or use a default layer CRS. Prompting is safest when you load unfamiliar data; leaving it unknown is convenient when loading many layers at once.
A tool you need is not in the Toolbox
By default only providers that need nothing beyond QGIS itself are active; algorithms that rely on external applications may need additional configuration in the Processing settings.
Free alternatives
| Tool | What its own site says | Source |
|---|---|---|
| QGIS | Free and open source desktop GIS under the GNU GPL; Windows, macOS, Linux, BSD | qgis.org |
| GRASS GIS | “A powerful computational engine for raster, vector, and geospatial processing”, with a Python API; free and open source for Windows, macOS, Linux, Docker or conda | grass.osgeo.org |
The two are not mutually exclusive: the QGIS manual describes QGIS as usable as a graphical front end for GRASS. For statistical work on the attributes you map, see how to choose a statistical test.
FAQ
Is QGIS software free?
Yes. The project states that its software is free of charge when downloaded from QGIS.org and is released under the GNU General Public License.
Which QGIS version should I install for a research project?
The project recommends the Long Term Release for users who value stability over the latest features. Whichever you choose, record the version number with your results.
Which file formats can QGIS open?
The project says QGIS supports a multitude of data sources and formats. Raster and vector files load through the Data Source Manager; the official sample session loads an ERDAS IMG raster and a GML vector file.
How do I save my work?
Use Project ► Save (Ctrl+S). Projects are stored as .qgz or .qgs files.
Sources (official documentation)
- QGIS download page, checked 2026-10-29
- QGIS project overview, checked 2026-10-29
- QGIS User Manual: Getting Started, checked 2026-10-29
- QGIS User Manual: QGIS GUI, checked 2026-10-29
- QGIS User Manual: Working with Projections, checked 2026-10-29
- QGIS User Manual: The Toolbox, checked 2026-10-29
- GRASS GIS, checked 2026-10-29
