João Freitas

The following is a summary of which HTTP fields/components are case sensitive.

https://misfra.me/2022/http-request-case-sensitivity/


I only recently learned that HTTP methods are case-sensitive. In order to save myself from future debugging headaches, I decided to do a quick search to see what else is case-sensitive.

This is what the RFC says. Real applications may treat things differently!

Case sensitive?ComponentReference
✅HTTP versionRFC
✅MethodRFC
❌URI schemeRFC
❌URI hostRFC
✅URI path, query, fragmentRFC
❌Header field nameRFC
✅Header field valuesNot explicit in the RFC. See below for some exceptions.
❌Transfer-coding header valueRFC
❌Connection header valueRFC
✅Body

Summary

Case-sensitive:

Case-insensitive:

#reads #preetam jinka #http