General tools
A simple ASCII to Base64 encoding utility
A simple Base64 to text decoding utility
A simple utility to URL-encode a string
A simple decoder for URL encoded strings
An utility for encoding/decoding Rot13 encrypted text
An utility for formatting/verifiying ugly JSON
An utility for formatting/verifiying ugly JavaScript
An utility for getting all information out of an UUID (timestamp + version)
An utility for decoding a JSON Web Token (JWT)
An utility for converting raw HTTP headers (for example from charles) to a JSON object
An utility for converting raw HTTP headers (for example from charles) to valid Golang code (fhttp library)
Antibot tools
An utility that converts ugly JavaScript into more readable code
Encode CloudFlare payloads using your custom key (lz-encrypt)
Decode Cloudflare payloads using a custom key (lz-encrypt)
Convert JSON responses from tls.peet.ws/api/all to client profiles for github.com/bogdanfinn/tls-client
External links
Collection of open-source tools and ressources to help reverse-engineering
RegExr is an online tool to learn, build, & test Regular Expressions (RegEx / RegExp)
Convert cURL commands to code in different languages
tls.peet.ws: find out what fingerprints your browser leaves on the web
The Cyber Swiss Army Knife, allows you to combine ~300 text operations
The best TLS client that serves all your needs
Git-style diff checker