{"slug":"api-webintel-api-workers-dev-api-security-tls-alpn-detector-d6004b","title":"Reports which newer HTTP protocols a site advertises","host":"api.webintel-api.workers.dev","method":"GET","resource":"https://api.webintel-api.workers.dev/api/security/tls-alpn-detector","category":"other","description":"Reports which newer HTTP protocols a site advertises: HTTP/3 (h3) and older draft or HTTP/2 alternatives in its Alt-Svc response header, and the Alt-Svc max-age. This is what the server announces, not a TLS ALPN negotiation: the fetch this tool makes cannot choose the protocol, so a site that negoti","price_listed":0.002,"price_asked":null,"state":"effects","state_label":"Not tested: has real-world effects","checks_7d":0,"answered_7d":0,"latency_ms_median":null,"reported_calls_30d":1,"reported_payers_30d":1,"networks":["eip155:5042","eip155:8453","solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp","xrpl:0"],"badge":"unverified","paid_checks_7d":0,"paid_ok_7d":0,"example_input":{"method":"GET","queryParams":{"domain":"example.com"},"type":"http"},"output_schema":{"$schema":"https://json-schema.org/draft/2020-12/schema","properties":{"input":{"additionalProperties":false,"properties":{"method":{"enum":["GET"],"type":"string"},"queryParams":{"properties":{"domain":{"description":"Domain name such as example.com (required)","type":"string"}},"required":["domain"],"type":"object"},"type":{"const":"http","type":"string"}},"required":["type","method"],"type":"object"},"output":{"properties":{"example":{"type":"object"},"type":{"type":"string"}},"required":["type"],"type":"object"}},"required":["input"],"type":"object"},"history":[],"description_full":"Reports which newer HTTP protocols a site advertises: HTTP/3 (h3) and older draft or HTTP/2 alternatives in its Alt-Svc response header, and the Alt-Svc max-age. This is what the server announces, not a TLS ALPN negotiation: the fetch this tool makes cannot choose the protocol, so a site that negotiates but does not send Alt-Svc will show as not advertised.","last_updated":"2026-10-23T18:43:04.905Z","schemes":["exact"]}