Crafting a unique encoding method (such as "k,v,..") presents distinct challenges compared to utilizing binary formats.
Even though it is technically still text-based, a custom encoding requires a rigid, singular format that must be painstakingly duplicated manually. This raises concerns about handling special characters like commas within keys or values, accommodating nested objects, and distinguishing between null values and empty strings or 'null'.
While JSON reigns supreme as the go-to format for WebSockets, manually writing out JSON is not recommended for data interchange - instead, serialization libraries should be leveraged on both ends of communication. The widespread adoption of JSON is attributed to various factors explored in other responses, although this does not necessarily mean it is always the optimal choice.
In addition to JSON, a binary serializer like BSON can also be employed seamlessly by replacing JSON.parse with FORMATX.parse where applicable.
The key requirements are:
Both clients and servers must have access to suitable serialization/deserialization mechanisms. JSON is favored due to its popularity and abundance of implementations available. While there are binary serialization options with Python and C# libraries, finding a compatible solution may require some effort.
The chosen serialization format must accurately represent the data. JSON excels here as it aligns closely with basic object structures and simple values, all while being schema-less. Although alternative formats offer specific advantages depending on the task at hand, JSON's versatility makes it a solid default choice.
Distinguishing features among different types of binary and text serializations often come down to superficial details. However, discussions around schema flexibility, extensibility, tool compatibility, metadata inclusion, post-compression payload sizes, adherence to existing protocols, and more can certainly influence decision-making.
All things considered, the crucial advice is to avoid reinventing the wheel with a new customized format. Unless, of course, you enjoy the challenge of creating something entirely novel or if there exists a highly specific use-case driving the need for a bespoke format.