[okok3857]

The tile size doesn't change, but the number of pixels per meter does as you note--distortion being greater the farther you get from the equator (in the Mercator projection).

The protomaps blog has some heady stuff you may enjoy reading: https://protomaps.com/blog/free-tier-maps. Felt apparently uses protomaps.js, which you can learn more about in that blog as well.

[moffkalast]

Well tile size in meters changes. Pixels stay the same but when a tile is rendered at a specific zoom level of meters/pixel on the screen it needs to be scaled differently and you may even need to request another ring of tiles to fill up the same FoV. Perhaps that was just a specific quirk of my application since I needed to overlay a metric grid with other data.

Thanks for the link, that was an interesting read. Though it seems odd to me that they insist on using AWS and complain about bandwidth when there are providers like Scaleway that do not charge for bandwidth usage at all. Though on the other hand they do only have EU locations so you can't use the CDN principle to reduce latency. But I'm sure people would wait a second longer if it meant a free API.