OpenLayers vs Leaflet! Performance and Functionality Comparison

Hasan Teoman Tıngır
4 min readDec 22, 2022

--

OpenLayers and are one of the most known mapping libraries on the industry used by thousands. Each of these libraries have its own pros and cons. Both of them have powerful side that the other has no efficient solution. Therefore it makes it hard to decide mapping library when it comes to develop a GIS project. Most of developers just met with the GIS had the same dilemma at some point in their life.

Looked over the sky when the night falling.. 
Fascinated by the stars rounding around our galaxy..
Asked themselves the sacred question..
OpenLayers, Leaflet or what else could be ?

I’m gonna start with the most basic answer; It depends on your needs. But of course I will explain what I mean with the “needs” to clarify your mind.

If your are planning to use very basic features of a map like viewing set of spatial data and make labelling and highlighting based on the attribute. No complex visualization achievements, no complex editor stuff. Then you may wish to proceed with the Leaflet.

Leaflet provides very basic API to integrate which can be implemented with just few steps. It underlies the complex logic and keeps the implementation very simple.

Demonstrated at above you can make the map works with just three lines of code. We can get the cities spatial data, create the map, create layer from geojson and attach to the map. That’s it!. No complex map initialization, no complex layer configuration and no need to manually convert the geojson object. Leaflet does everything for you.

Leaflet can understand different type of geojson if given follows valid specification. It can read Feature, FeatureCollection or even array of Features.

Is this what you want ? Then here you go! Leaflet is what you are looking for! No ? Not even close ? You need some complex operations with the spatial data, some spatial analysis at frontend, custom layer configuration or external raster layer configurations such WMTS, custom logic when loading the data, is that what you are looking for ? Then OpenLayers might be what you are looking for.

But keep you in mind that if you are planning to visualize large number of data sets at a time like over 50k geometries, you may want to stick with the Leaflet — or — OpenLayers with VectorTile server. Leaflet has at least 4x performance than the OpenLayers (by my experience). While you can render 20k geometry with OpenLayers, Leaflet can render up to 100k geometries without serious performance problems. Sure thing it depends the number of edge that your geometry have.

But you need to be aware of it won’t be that easy to implement like Leaflet 🙂 But it won’t be problem because there are dozen of documentation and examples over the web and you can just copy paste and you are good to go!

Let’s take a look how it looks like

In order to initialize map you need configured view, map element and layers including base layer which we use OSM. Then you need to create vector layer to visualize geometries on the map. Vector layers needs a source where you can load geometries with different strategies. Finally you can register the layer to the map and we are good to go.

Want to know more about the OSM? (Open Street Map) Checkout it below post!

Let Discover The Unsung Hero OpenStreetMap (OSM)

It might looks confusing if you never used before but I can tell you that not hard that it looks. OpenLayers provides well structured and OOP solution which makes your codebase clean and sense. There is logical relation between the elements in the structure. When you used once you’ll get used to it for good.

Overall both of them very powerful technologies. Personally I’m more comfortable to work with OOP environment so I would rather to work with the OpenLayers over the Leaflet. But as I said at the beginning everything depend on your needs and your style.

This post took way too long than I expected 🙂 I had to go now 🙂 I hope I help you to clarify your mind to make the decision!

Originally published at https://blog.teoman.me on December 22, 2022.

--

--