ua-tracer by Paul Kinlan

ua-tracer

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

← all traces

Trace 6j4UTU46

First seen: 2026-06-22 19:31:51.328 UTC
User-Agent: Mozilla/5.0 (iPhone; CPU iPhone OS 27_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/24A5355q Twitter for iPhone/12.1

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
2026-06-22 19:31:51.328 UTC +0 ms homepage GET Mozilla/5.0 (iPhone; CPU iPhone OS 27_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/24A5355q Twitter for iPhone/12.1
request headers (13) 
{
  "accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
  "accept-encoding": "gzip, deflate, br, zstd",
  "accept-language": "en-US,en;q=0.9",
  "host": "ua-tracer.paulkinlan-ea.deno.net",
  "priority": "u=0, i",
  "referer": "https://t.co/",
  "sec-fetch-dest": "document",
  "sec-fetch-mode": "navigate",
  "sec-fetch-site": "cross-site",
  "traceparent": "00-02b74f7035740564b2f583af353e513e-c07dd1d5ae4b2fcd-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (iPhone; CPU iPhone OS 27_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/24A5355q Twitter for iPhone/12.1",
  "via": "HTTP/2 ord.vultr.prod.deno-cluster.net"
}