ua-tracer by Paul Kinlan

ua-tracer

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

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Trace T7ww0gpK

First seen: 2026-07-02 13:49:02.699 UTC
User-Agent: Mozilla/5.0 (compatible; DemoBot/1.0; +https://example.com)

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
2026-07-02 13:49:02.699 UTC +0 ms homepage GET Mozilla/5.0 (compatible; DemoBot/1.0; +https://example.com)
request headers (8) 
{
  "accept": "*/*",
  "host": "uatracer.com",
  "traceparent": "00-ac896eaf4305c303285f2c870b3f7cb5-8f8659643911f099-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (compatible; DemoBot/1.0; +https://example.com)",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net",
  "x-deno-userspace-traceparent": "00-ac896eaf4305c303285f2c870b3f7cb5-c7c25fc32a6063c3-01",
  "x-deno-userspace-tracestate": ""
}
2026-07-02 13:49:04.579 UTC +1880 ms CSS GET curl/8.20.0
request headers (8) 
{
  "accept": "*/*",
  "host": "uatracer.com",
  "traceparent": "00-929ebcae83c553cecfe9f2291986a998-c07bd85f5c131e2d-01",
  "tracestate": "",
  "user-agent": "curl/8.20.0",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net",
  "x-deno-userspace-traceparent": "00-929ebcae83c553cecfe9f2291986a998-80f8d7ed684a6b41-01",
  "x-deno-userspace-tracestate": ""
}
2026-07-02 13:49:05.451 UTC +2752 ms JS GET curl/8.20.0
request headers (8) 
{
  "accept": "*/*",
  "host": "uatracer.com",
  "traceparent": "00-c0d561ae94ca61c70eb46221a62095a2-093eb42670171e3c-01",
  "tracestate": "",
  "user-agent": "curl/8.20.0",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net",
  "x-deno-userspace-traceparent": "00-c0d561ae94ca61c70eb46221a62095a2-7f584b250f8b71c2-01",
  "x-deno-userspace-tracestate": ""
}
2026-07-02 13:49:06.393 UTC +3694 ms CSS background-image GET curl/8.20.0
request headers (8) 
{
  "accept": "*/*",
  "host": "uatracer.com",
  "traceparent": "00-55502524b368240d5f523cf8dfe053a6-bf5d3a519eea5b33-01",
  "tracestate": "",
  "user-agent": "curl/8.20.0",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net",
  "x-deno-userspace-traceparent": "00-55502524b368240d5f523cf8dfe053a6-a7ee02a1c6aa00c3-01",
  "x-deno-userspace-tracestate": ""
}
2026-07-02 13:49:07.278 UTC +4579 ms JS executed beacon GET curl/8.20.0
request headers (8) 
{
  "accept": "*/*",
  "host": "uatracer.com",
  "traceparent": "00-170ada53b8b818df779eef4643d519c1-3aed0546684d14b2-01",
  "tracestate": "",
  "user-agent": "curl/8.20.0",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net",
  "x-deno-userspace-traceparent": "00-170ada53b8b818df779eef4643d519c1-74eb4dc885f1d2e4-01",
  "x-deno-userspace-tracestate": ""
}

Client-side resource waterfall

JS executed (beacon hit) but no resource-timing payload was posted (UA may block sendBeacon/fetch or strip the body).