Best Practices for Sending Extensive Filters in GET Requests Without Exceeding Header Limits

I'm working on an application that allows users to filter by location. In order to do this, I'm adding my city filters into a query parameter. For example, if someone selects California I would encode it in base64 and then add the filters to my query parameter. Here's the filter object that gets encoded:

[{city: "San Francisco", state: "California", country: "USA"}, {...}, {...}]

Here's what the request will look like after encoding:

http://localhost:3001/api/v1/companies?offset=0&limit=50&locs=W3siY2l0eSI6IkFsYW1lZGEiLCJzdGF0ZSI6IkNhbGlmb3JuaWEiLCJjb3VudHJ5IjoiVW5pdGVkIFN0YXRlcyJ9LHsiY2l0eSI6IkFuYWhlaW0iLCJzdGF0ZSI6IkNhbGlm...

However, after a certain number of filters, I run up against header limits (i.e. I can't fit more information into the request header).

What's the best-practice way of handling this? Should I send a POST request instead, or is that frowned upon?

FYI — Users can click into a state and select/unselected specific cities. For example, someone could click into California and uncheck San Francisco and Los Angeles .

The request URI is not considered a header, but you still may run into limits. Usually it's recommended to stay under 2048 bytes.

If you go above this, switch to a different HTTP method (QUERY, POST) and use the request body. QUERY is more appropriate for read operations, supported by browsers but not yet by every server. POST is a good second choice.