The following conversation happened on twitter, @JamesNK being the author of JSON.net: https://twitter.com/jonathan_oliver/status/332227095616966656
From: Jonathan Oliver @jonathan_oliver To: @JamesNK
Are the static JsonConvert.DeserializeObject methods thread safe? Getting some strange errors using 5.0.4 and 5.0.5.
Response:
James Newton-King ♔ @JamesNK 8 May 2013 @jonathan_oliver
Yes. Create an issue on GitHub if they’re not
Response:
Jonathan Oliver @jonathan_oliver 9 May 2013
@JamesNK It turns out a ContractResolver attached to a static JsonSerializerSettings object I used with JsonConvert wasn't thread safe.
I do not see that a bug was ever filed, but this does hint that the design of them is supposed to be thread safe, but there maybe implementation specific ways to ruin that or it might not be as a whole.