# StatusCodeFYI

> The Universal Status Code Encyclopedia

Comprehensive reference for HTTP, SMTP, gRPC, DNS, WebSocket, FTP, and SIP status codes — with examples, comparisons, and interactive tools.

## Stats

- 258 status codes across 7 protocols
- 172 how-to guides
- 360 glossary terms
- 70 debugging scenarios
- 51 RFC/standard specifications

## Protocols

- [HTTP Status Codes](https://statuscodefyi.com/http/)
- [SMTP Reply Codes](https://statuscodefyi.com/smtp/)
- [gRPC Status Codes](https://statuscodefyi.com/grpc/)
- [DNS Response Codes](https://statuscodefyi.com/dns/)
- [WebSocket Close Codes](https://statuscodefyi.com/websocket/)
- [FTP Reply Codes](https://statuscodefyi.com/ftp/)
- [SIP Response Codes](https://statuscodefyi.com/sip/)

## Resources

- [Guides](https://statuscodefyi.com/guides/) — 172 how-to articles
- [Glossary](https://statuscodefyi.com/glossary/) — 360 technical terms
- [Comparisons](https://statuscodefyi.com/compare/) — Side-by-side code comparisons
- [Debugging Scenarios](https://statuscodefyi.com/scenarios/) — 70 playbooks
- [Specifications](https://statuscodefyi.com/specs/) — 51 RFC references
- [Decision Guides](https://statuscodefyi.com/decisions/) — Interactive decision trees

## Tools

- [HTTP Header Checker](https://statuscodefyi.com/tools/header-checker/)
- [Status Code Tester](https://statuscodefyi.com/tools/status-tester/)
- [Mock Server](https://statuscodefyi.com/tools/mock-server/)
- [CORS Checker](https://statuscodefyi.com/tools/cors-checker/)
- [JWT Decoder](https://statuscodefyi.com/tools/jwt-decoder/)
- [Redirect Tracer](https://statuscodefyi.com/tools/redirect-tracer/)

## Machine-Readable Access

- Markdown: Append `.md` to any URL (e.g. https://statuscodefyi.com/glossary.md)
- [RSS Feed](https://statuscodefyi.com/feed/rss/)
- [Atom Feed](https://statuscodefyi.com/feed/atom/)
- [Sitemap](https://statuscodefyi.com/sitemap.xml)
- [Full Content Index](https://statuscodefyi.com/llms-full.txt)
- [Developer Docs](https://statuscodefyi.com/developers/)