ua-tracer by Paul Kinlan

trace sYk2WS0E

ua-tracer

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

← all traces

Trace sYk2WS0E

First seen: 2026-06-22 12:06:35.634 UTC
User-Agent: Mastodon/4.3.6 (http.rb/5.2.0; +https://social.synesthesia.co.uk/) Bot
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
2026-06-22 12:06:35.634 UTC +0 ms homepage GET Mastodon/4.3.6 (http.rb/5.2.0; +https://social.synesthesia.co.uk/) Bot
request headers (10) 
{
  "accept": "text/html",
  "accept-encoding": "gzip",
  "accept-language": "en, *;q=0.5",
  "connection": "close",
  "date": "Mon, 22 Jun 2026 12:06:35 GMT",
  "host": "ua-tracer.paulkinlan-ea.deno.net",
  "traceparent": "00-13cd2a50495b1ae0e83c004d08da6137-dfc295d9fea19d96-01",
  "tracestate": "",
  "user-agent": "Mastodon/4.3.6 (http.rb/5.2.0; +https://social.synesthesia.co.uk/) Bot",
  "via": "HTTP/1.1 ams.vultr.prod.deno-cluster.net"
}
2026-06-22 12:06:36.027 UTC +393 ms Open Graph image GET Mastodon/4.3.6 (http.rb/5.2.0; +https://social.synesthesia.co.uk/)
request headers (8) 
{
  "accept-encoding": "gzip",
  "connection": "close",
  "date": "Mon, 22 Jun 2026 12:06:35 GMT",
  "host": "ua-tracer.paulkinlan-ea.deno.net",
  "traceparent": "00-d30546b677b7e09b59d250933e8272cd-0bb823925fcc014c-01",
  "tracestate": "",
  "user-agent": "Mastodon/4.3.6 (http.rb/5.2.0; +https://social.synesthesia.co.uk/)",
  "via": "HTTP/1.1 ams.vultr.prod.deno-cluster.net"
}