ua-tracer by Paul Kinlan

ua-tracer

what does a user agent actually fetch, follow & run?

← all traces

Trace W73ZUG64

First seen: 2026-06-23 12:14:06.012 UTC
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Firefox/102.0

What this user agent did

Directly-referenced assets:

✗ fetched CSS ✗ fetched JS ✗ fetched image ✗ fetched font (HTML)

Document-level link hints:

✓ fetched favicon ✗ fetched apple-touch-icon ✗ fetched web manifest ✗ fetched preload ✗ fetched prefetch

Second-level follows (proves it parsed the linking file):

✗ followed CSS background-image ✗ followed CSS @font-face ✗ followed manifest icon ✗ followed CSS @import

Frames (does it descend into iframes?):

✗ fetched iframe document ✗ descended into iframe (loaded inner image)

Reporting (a report-only CSP is violated by inline styles; reports can arrive via HTTP headers with no JS, or via in-page beacons):

✗ sent a CSP/Reporting report (any path) ✗ delivered via report-uri/Report-To header (no JS) ✗ delivered via in-page beacon (securitypolicyviolation / ReportingObserver)

Social embed (Open Graph / Twitter card images):

✗ fetched og:image ✗ fetched twitter:image

JavaScript execution:

✗ EXECUTED classic JS ✗ EXECUTED ES module ✗ posted client timing

Server-side request waterfall

Every request the server received for this trace, in receive order. +ms is the delta from the homepage request.

ReceivedΔKindMethodUser-Agent
2026-06-23 12:14:06.012 UTC +0 ms homepage GET Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Firefox/102.0
request headers (9) 
{
  "accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9",
  "accept-encoding": "gzip, deflate",
  "accept-language": "zh-CN,zh;q=0.9,en;q=0.8",
  "cache-control": "max-age=0",
  "host": "uatracer.com",
  "traceparent": "00-508a74c0cf4a20c6c4e8c89a3a888a34-c587d5a158e48659-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Firefox/102.0",
  "via": "HTTP/1.1 ord.vultr.prod.deno-cluster.net"
}
2026-06-23 12:14:14.315 UTC +8303 ms favicon GET Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/116.0
request headers (8) 
{
  "accept": "*/*",
  "accept-encoding": "gzip, deflate",
  "connection": "keep-alive",
  "host": "uatracer.com",
  "traceparent": "00-4989f24598ce12848e6aa674f9bc0d36-fa22f5d71aef1eeb-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/116.0",
  "via": "HTTP/1.1 ord.vultr.prod.deno-cluster.net"
}