Since 25 September 2026 the CARTO basemaps (Positron, Dark Matter, Voyager) are only served with an API key, sent as the key query parameter (…/{z}/{x}/{y}.png?key=YOUR_KEY). Without a key, every tile is an “API KEY REQUIRED” image.
Get a key: carto.com/basemaps/apikey — free for non-commercial use up to 5 million tile requests a month (commercial use up to 1 million).
Used by CARTO Positron and CARTO Dark Matter.