Map Clustering Is Not My Favorite
Greg Sadetsky passionately argues that map clustering, once a necessary evil to handle browser limitations, is now an obsolete and frustrating user experience. He contends that modern GPU-accelerated mapping libraries make it possible to display all data points directly and efficiently. This opinionated take on a common web development pattern challenges prevailing practices, resonating with HN's technical audience who appreciate strong, well-reasoned critiques.
The Lowdown
The author, Greg Sadetsky, shares a long-held "rant" about map clustering, a widely adopted technique he believes is no longer relevant or effective in modern web mapping. He traces its origins to the performance limitations of early web browsers from two decades ago and asserts that today's advanced technology has rendered it obsolete, while also highlighting its inherent user experience flaws.
- Historical Necessity: Map clustering emerged around 20 years ago to mitigate the performance issues of older browsers struggling to render thousands of individual DOM elements for map markers.
- Early Solutions: Initial strategies to manage excessive points included map paging, heatmaps, or pre-baking points into static images.
- Critique of Clustering's UX: Sadetsky uses Atlas Obscura's map as a prime example to illustrate his grievances, highlighting that clusters:
- Do not immediately reveal their contained content, forcing users to zoom in repeatedly without certainty, akin to a non-transparent Kinder Surprise or an unopenable matryoshka doll.
- Sometimes fail to disclose their content even after zooming, particularly when points are extremely close or co-located.
- Often present a jarring visual experience by revealing points far from the original cluster's perceived location upon zooming, which he likens to an "atom splitting."
- Are visually strenuous, as requiring the eye and brain to decipher numbers on a map is an inefficient and unproductive way to process information.
- Modern Mapping Capabilities: He asserts that contemporary mapping technology, leveraging GPU and shader-based rendering (similar to video game engines), is incredibly fast and efficient. This advancement allows for the direct display of thousands of points without performance degradation, citing technologies like MapLibre GL JS as exemplary.
- Proposed Alternative: To demonstrate his point, Sadetsky created a custom map using Atlas Obscura data, Protomaps, and MapLibre GL JS. This map displays all points directly without clustering, maintaining speed and responsiveness. He suggests "density dots" (slightly opaque overlayed dots) as a potentially superior visual method for conveying density compared to traditional clusters.
In conclusion, the author argues that while map clustering served a vital purpose in its era, it has definitively outlived its utility. He urges developers to abandon clustering and fully leverage the power of modern mapping libraries to display all data points directly, heralding a "post-cluster" age where maps can simply "be."