Web GIS (Web-based Geographic Information System) is a GIS that runs in a web browser and is served over the internet, rather than as desktop software. It lets people view, explore, query and analyze geospatial data from anywhere, without the need for any software beyond the browser they already have.
The term covers a spectrum. At the simplest end is a static webmap; at the richest end, a full system with layer control, search and filtering, feature querying, access permissions and live data. What they share is the core idea of moving GIS off the individual desktop and onto the web, so a map becomes something you send as a link rather than a file you install software to open.
Web GIS is the natural complement to desktop tools like QGIS: the heavy lifting still happens on the desktop, but the results become accessible to everyone through the browser.
At a basic level, a Web GIS lets anyone open your map in a browser and pan, zoom and switch between layers or predefined themes. Clicking on a feature makes its attributes appear, so a viewer can investigate the data without touching QGIS.
Beyond viewing, most Web GIS platforms let you search and filter data, share a map with a single URL, embed it directly inside another website or internal portal, and expose your layers as standard web services (WMS, WFS) that other software can consume. Richer setups add editing, dashboards and analytical tools on top. The common thread is that all of this happens live in the browser, always reflecting the current state of your data.
These three are not competing products so much as three places where the GIS work happens, each suited to a different job and a different audience.
Desktop GIS is where the real work gets done. Software like QGIS, installed on a computer, is the workshop: it holds the full data, the heavy layers, the set of processing tools and the cartography, and it's where analysts build projects, run spatial analysis and style the maps. It's powerful and complete, but it lives on one machine and assumes a trained user.
Mobile GIS takes a slice of that project into the field. A native app on a phone or tablet, such as Mergin Maps, is built for capturing and updating data on site, often offline, with GPS and simple forms. It's designed for field crews who need to record what they see, not to analyse it. The scope is deliberately narrow because the job is data collection, not sophisticated analysis. An interesting aspect of Mobile GIS is how it can take full advantage of the hardware capabilities during data capture: The GPS, camera, gyroscope and magnetometer can all be used to enhance the data with a level of detail and accuracy that is usually not found in popular online GIS data sources.
Web GIS makes the results accessible to everyone through a browser, with nothing to install. It's the shop window rather than the workshop: it leans toward viewing, exploring and sharing a project rather than building or editing it, and it's aimed at the widest audience, including the managers, clients and stakeholders who need the overview but never open a GIS.
The three are complementary, and in practice they form a loop. Field teams collect data with mobile GIS, analysts process and style it in desktop GIS, and Web GIS publishes the current picture back out to everyone. Mergin Maps is built to keep that loop in sync, so an edit made in the field or on the desktop flows through to the shared map online.
Most of the people who need to understand a spatial project never open a GIS. Managers, clients, planners and other stakeholders need the overview: where things are, what's been done, what's pending to be completed. They shouldn't have to learn desktop software or wait for someone to export a static PDF to get it.
Web GIS closes that gap. It turns your project into something anyone can open and understand in seconds, giving decision-makers a live, high-level view they can explore themselves.
The easiest way to picture it: just as you need Google Maps to navigate your city (the most widely used Web GIS in the world), you need a Web GIS to navigate your project. Google Maps didn't put a cartographer at everyone's desk; it made spatial information something accessible and useful for everyday use. A Web GIS does the same for your organisation's data.
Think of your Web GIS as the shared window onto your project, not as a replacement for your analytical tools. It works best as the coordination layer that keeps everyone looking at the same picture: field teams collect data, your analysts process and interpret it in desktop QGIS, and the Web GIS is where management, analysts and field crews all see the current state come together.
That framing shapes how you set it up. Curate it for oversight rather than analysis; showing the layers and themes that tell the project's story at a glance, with clear symbology and sensible default extents, and keeping the dense technical layers in the desktop project where they belong. Lean on map themes to offer a few purposeful views instead of an overwhelming layer list. Kept lightweight and current, a Web GIS becomes the common reference everyone trusts, while the deep analytical work stays in QGIS.
Yes. Because a Web GIS runs entirely in the browser, it works on any device with an internet connection and a modern browser, with nothing to install.
That said, tablets tend to give the best experience. The larger screen makes it far easier to read the map, work with the layers panel and inspect feature attributes than on a phone, where a Web GIS is perfectly usable but naturally cramped. It's worth keeping the distinction clear, too: a browser-based Web GIS is for viewing and exploring your project, whereas dedicated field data collection is the job of a native mobile app like Mergin Maps.
Under the hood, a Web GIS is a client-server system with three main parts.
The flow is a simple conversation. As you pan or zoom, the browser client requests the map it needs; the server renders it from the data and sends it back; the client draws it on screen. Because the server renders from the same project you built on the desktop, the map online looks the same as it does in QGIS.
Yes, and it's an area we're actively developing. Mergin Maps lets you take a project you've built in QGIS and bring it online: your survey and other layers are displayed and explored in the Map tab of the dashboard, complete with a layers panel, the legends and map themes you defined in QGIS, and click-to-identify on any feature. Because the map is rendered from your QGIS project itself, the symbology online matches your desktop exactly, and it refreshes automatically as your data changes.
You can share a webmap with anyone via a URL, or embed it in your own website with a simple HTML iframe, without recipients needing to log in. Your layers are also available as read-only OGC web services (WMS and WFS), and for teams that want to go further, a custom map-script.js lets you build tailored webmap applications on top of the underlying OpenLayers map.
Today these capabilities sit at the viewing, sharing and coordination end of the Web GIS spectrum. The deeper editing and analysis stay in desktop QGIS and the mobile app, and we're expanding toward a fully managed QGIS cloud experience.
