ua-tracer by Paul Kinlan

ua-tracer

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

← all traces

Trace NfM08SpW

First seen: 2026-06-22 18:14:33.993 UTC
User-Agent: Mastodon/4.5.10 (http.rb/5.3.1; +https://social.lostinok.com/) Bot

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 18:14:33.993 UTC +0 ms homepage GET Mastodon/4.5.10 (http.rb/5.3.1; +https://social.lostinok.com/) Bot
request headers (10) 
{
  "accept": "text/html",
  "accept-encoding": "gzip",
  "accept-language": "en, *;q=0.5",
  "connection": "close",
  "date": "Mon, 22 Jun 2026 18:14:32 GMT",
  "host": "ua-tracer.paulkinlan-ea.deno.net",
  "traceparent": "00-423b530a2584ba515e7ec4a16eebad64-4cf818f672dde671-01",
  "tracestate": "",
  "user-agent": "Mastodon/4.5.10 (http.rb/5.3.1; +https://social.lostinok.com/) Bot",
  "via": "HTTP/1.1 ord.vultr.prod.deno-cluster.net"
}
2026-06-22 18:14:34.732 UTC +739 ms Open Graph image GET Mastodon/4.5.10 (http.rb/5.3.1; +https://social.lostinok.com/)
request headers (10) 
{
  "accept-encoding": "gzip",
  "connection": "close",
  "date": "Mon, 22 Jun 2026 18:14:34 GMT",
  "host": "ua-tracer.paulkinlan-ea.deno.net",
  "traceparent": "00-18cb0d637faf444c438f0745ccd03c98-e8a61b49e711cc43-01",
  "tracestate": "",
  "user-agent": "Mastodon/4.5.10 (http.rb/5.3.1; +https://social.lostinok.com/)",
  "via": "HTTP/1.1 ord.vultr.prod.deno-cluster.net",
  "x-deno-userspace-traceparent": "00-18cb0d637faf444c438f0745ccd03c98-f8f3c4e19511143b-01",
  "x-deno-userspace-tracestate": ""
}