…lint was the name originally given to a particular program that flagged some suspicious and non-portable constructs (likely to be bugs) in C language source code. The term is now applied generically to tools that flag suspicious usage in software written in any computer language… — wikipedia
My taste is on tooling is more about online tools than browser extensions these days. Especially when it comes to small things like text manipulation and generators.
Here is a non-comprehensive list of online lint tools in various areas I found useful.
- Regular expression — https://regex101.com/
- JSON — https://jsonformatter.curiousconcept.com/
- YAMLlint — http://yamllint.com/
- CSSLint — http://csslint.net/
- JSON Schema generator — http://jsonschema.net — http://jsonschemalint.com/draft4/
- Base64 encode/decode — https://base64encode.org/
- CSV lint — http://csvlint.io/
- +1 gitignore generator — https://gitignore.io/
- +1 Dev Tools Online! (xsd generator and a lot more) — https://devutilsonline.com/