# WebTransport Day (webtransport.day)

> WebTransport Day is an independent resource for web developers building realtime apps: WebTransport and the web platform, plus hands-on coverage of the AI coding tools developers use to build them. It is not affiliated with the public echo server that previously ran on this domain.

Full text of all published pages and datasets: https://webtransport.day/llms-full.txt
Each content page has a plain-markdown version at its URL plus `index.md` (for example https://webtransport.day/guides/what-is-webtransport/index.md).
Content dates come from each page's front matter or file history; technical pages also state a "Facts checked" date and link their sources.

## WebTransport

- [Public WebTransport echo servers](https://webtransport.day/echo-server/): what an echo server is, the history of the one that ran on this domain, and other public and open-source test servers (checked 2026-10-28).
- [WebTransport tester](https://webtransport.day/tools/webtransport-tester/): free client-side tool that connects your browser to a WebTransport URL you choose, shows browser capabilities, a timeline and round-trip timings.
- [Server-readiness checklist](https://webtransport.day/tools/server-checklist/): seven things a WebTransport server needs, with a copyable what-to-check-next report.
- [WebTransport and serverless or edge platforms](https://webtransport.day/serverless/): what Cloudflare, AWS, Google Cloud, Vercel, Fastly and others document about running WebTransport (checked 2026-10-28).

## Guides

- [What is WebTransport?](https://webtransport.day/guides/what-is-webtransport/): streams, datagrams, HTTP/3, QUIC, standards status and browser support.
- [WebTransport vs WebSocket](https://webtransport.day/guides/webtransport-vs-websocket/): sourced comparison, with notes on WebRTC data channels.
- [WebTransport client and server libraries](https://webtransport.day/guides/webtransport-client-libraries/): verified libraries for Rust, Go, Python, Node.js, .NET and Deno.
- [Debugging WebTransport handshake errors](https://webtransport.day/guides/debug-webtransport-handshake-errors/): certificates, serverCertificateHashes, HTTP/3, UDP, origin and path checks.
- [Test WebTransport locally](https://webtransport.day/guides/test-webtransport-locally/): run an example server and connect from a browser.
- [Learn WebTransport](https://webtransport.day/learn/webtransport/): the guides as an ordered seven-step path.

## AI coding

- [AI coding for web and realtime developers](https://webtransport.day/ai-coding/): explainers and tested write-ups of the AI coding tools used to build realtime web apps. No rankings.

## Reference data (also as JSON)

- [Browser support matrix](https://webtransport.day/browser-support/): built from MDN browser-compat-data. JSON: https://webtransport.day/data/webtransport-browser-support.json
- [Specification status](https://webtransport.day/spec-status/): W3C, IETF drafts and RFCs. JSON: https://webtransport.day/data/webtransport-spec-status.json
- [Implementations directory](https://webtransport.day/implementations/): libraries with licence, latest release and last commit. JSON: https://webtransport.day/data/webtransport-implementations.json
- [Glossary](https://webtransport.day/glossary/): definitions with primary sources. JSON: https://webtransport.day/data/webtransport-glossary.json
- [API cheat sheet](https://webtransport.day/cheatsheet/): snippets checked against MDN and the W3C spec. JSON: https://webtransport.day/data/webtransport-cheatsheet.json
- [Data index](https://webtransport.day/data/)

## Policies and updates

- [Editorial policy and methodology](https://webtransport.day/editorial-policy/)
- [Disclosure](https://webtransport.day/disclosure/)
- [Corrections log](https://webtransport.day/corrections/)
- [Changelog](https://webtransport.day/changelog/): dated list of meaningful content updates.

## Optional

- [RSS feed](https://webtransport.day/rss.xml)
- [Sitemap](https://webtransport.day/sitemap-index.xml)