ua-tracer by Paul Kinlan

ua-tracer

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

← all traces

Trace ERK13MUC

First seen: 2026-07-03 07:31:47.627 UTC
User-Agent: HackerNews/1566 CFNetwork/3860.600.12 Darwin/25.5.0
Bot verification: Not a known bot (no IP-range check applies).

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
2026-07-03 07:31:47.627 UTC +0 ms homepage GET HackerNews/1566 CFNetwork/3860.600.12 Darwin/25.5.0
request headers (11) 
{
  "accept": "*/*",
  "accept-encoding": "gzip, deflate, br",
  "accept-language": "en-CA,en-US;q=0.9,en;q=0.8",
  "host": "uatracer.com",
  "priority": "u=3",
  "traceparent": "00-e894640d55bd646693b985d3d0c21816-a138b8f304e325a0-01",
  "tracestate": "",
  "user-agent": "HackerNews/1566 CFNetwork/3860.600.12 Darwin/25.5.0",
  "via": "HTTP/2 ord.vultr.prod.deno-cluster.net",
  "x-deno-userspace-traceparent": "00-e894640d55bd646693b985d3d0c21816-f828d7b8304568ab-01",
  "x-deno-userspace-tracestate": ""
}
2026-07-03 07:31:50.206 UTC +2579 ms Open Graph image GET HackerNews/1566 CFNetwork/3860.600.12 Darwin/25.5.0
request headers (12) 
{
  "accept": "*/*",
  "accept-encoding": "gzip, deflate, br",
  "accept-language": "en-CA,en-US;q=0.9,en;q=0.8",
  "cookie": "ua-tracer-trace=ERK13MUC",
  "host": "uatracer.com",
  "priority": "u=3",
  "traceparent": "00-ef7ee422bdaba30e6113614d42604333-08874073fa2e54c6-01",
  "tracestate": "",
  "user-agent": "HackerNews/1566 CFNetwork/3860.600.12 Darwin/25.5.0",
  "via": "HTTP/2 ord.vultr.prod.deno-cluster.net",
  "x-deno-userspace-traceparent": "00-ef7ee422bdaba30e6113614d42604333-4cf7ce092a134917-01",
  "x-deno-userspace-tracestate": ""
}