Which, if you take the base64 encoded string, strip off the control characters, pad it out to a valid base64 string, you get
"eyJhZ2VuZGEiOnsiaWQiOm51bGwsImNlbnRlciI6Wy0xMTUuOTI1LDM2LjAwNl0sImxvY2F0aW9uIjpudWxsLCJ6b29tIjo2LjM1MzMzMzMzMzMzMzMzMzV9LCJhbmltYXRpbmciOmZhbHNlLCJiYXNlIjoic3RhbmRhcmQiLCJhcnRjYyI6ZmFsc2UsImNvdW50eSI6ZmFsc2UsImN3YSI6ZmFsc2UsInJmYyI6ZmFsc2UsInN0YXRlIjpmYWxzZSwibWVudSI6dHJ1ZSwic2hvcnRGdXNlZE9ubHkiOmZhbHNlLCJvcGFjaXR5Ijp7ImFsZXJ0cyI6MC44LCJsb2NhbCI6MC42LCJsb2NhbFN0YXRpb25zIjowLjgsIm5hdGlvbmFsIjowLjZ9fQ==", which decodes into:
I only know this because I've spent a ton of time working with the NWS data - I'm founding a company that's working on bringing live local weather news to every community that needs it - https://www.lwnn.news/
Nesting, mostly (having used that trick a lot, though I usually sign that record if originating from server).
I've almost entirely moved to Rust/WASM for browser logic, and I just use serde crate to produce compact representation of the record, but I've seen protobufs used as well.
Otherwise you end up with parsing monsters like ?actions[3].replay__timestamp[0]=0.444 vs {"actions": [,,,{"replay":{"timestamp":[0.444, 0.888]}]}
Sorry but this is legitimately a terrible way to encode this data. The number 0.8 is encoded as base64 encoded ascii decimals. The bits 1 and 0 similarly. URLs should not be long for many reasons, like sharing and preventing them from being cut off.
Links with lots of data in them are really annoying to share. I see the value in storing some state there, but I don’t think there is room for much of it.
What makes them annoying to share? I bet it's more an issue with the UX of whatever app or website you're sharing the link in. Take that stackoverflow link in the comment you're replying to, for example: you can see the domain and most of the path, but HN elides link text after a certain length because it's superfluous.
If you go there, that's the URL you get. However, if you do anything with the map, your URL changes to something like
https://radar.weather.gov/?settings=v1_eyJhZ2VuZGEiOnsiaWQiO...
Which, if you take the base64 encoded string, strip off the control characters, pad it out to a valid base64 string, you get
"eyJhZ2VuZGEiOnsiaWQiOm51bGwsImNlbnRlciI6Wy0xMTUuOTI1LDM2LjAwNl0sImxvY2F0aW9uIjpudWxsLCJ6b29tIjo2LjM1MzMzMzMzMzMzMzMzMzV9LCJhbmltYXRpbmciOmZhbHNlLCJiYXNlIjoic3RhbmRhcmQiLCJhcnRjYyI6ZmFsc2UsImNvdW50eSI6ZmFsc2UsImN3YSI6ZmFsc2UsInJmYyI6ZmFsc2UsInN0YXRlIjpmYWxzZSwibWVudSI6dHJ1ZSwic2hvcnRGdXNlZE9ubHkiOmZhbHNlLCJvcGFjaXR5Ijp7ImFsZXJ0cyI6MC44LCJsb2NhbCI6MC42LCJsb2NhbFN0YXRpb25zIjowLjgsIm5hdGlvbmFsIjowLjZ9fQ==", which decodes into:
{"agenda":{"id":null,"center":[-115.925,36.006],"location":null,"zoom":6.3533333333333335},"animating":false,"base":"standard","artcc":false,"county":false,"cwa":false,"rfc":false,"state":false,"menu":true,"shortFusedOnly":false,"opacity":{"alerts":0.8,"local":0.6,"localStations":0.8,"national":0.6}}
I only know this because I've spent a ton of time working with the NWS data - I'm founding a company that's working on bringing live local weather news to every community that needs it - https://www.lwnn.news/