ua-tracer by Paul Kinlan

ua-tracer

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

← all traces

Trace AxTu95e4

First seen: 2026-07-02 12:55:16.328 UTC
User-Agent: Mozilla/5.0 (compatible; YandexBot/3.0; +http://yandex.com/bots)

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 12:55:16.328 UTC +0 ms homepage GET Mozilla/5.0 (compatible; YandexBot/3.0; +http://yandex.com/bots)
request headers (6) 
{
  "accept-encoding": "gzip",
  "host": "uatracer.com",
  "traceparent": "00-b9d2aafb18d9f16cb222e4395c71b42b-22ca342fdf23b407-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (compatible; YandexBot/3.0; +http://yandex.com/bots)",
  "via": "HTTP/1.1 ams.vultr.prod.deno-cluster.net"
}
2026-07-02 12:55:18.127 UTC +1799 ms JS GET Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; GPTBot/1.3; +https://openai.com/gptbot)
request headers (6) 
{
  "accept-encoding": "gzip",
  "host": "uatracer.com",
  "traceparent": "00-9b1b204da0515aec377d7467604573e1-a11f9a41ae7ebd07-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; GPTBot/1.3; +https://openai.com/gptbot)",
  "via": "HTTP/1.1 ams.vultr.prod.deno-cluster.net"
}
2026-07-02 12:55:18.134 UTC +1806 ms ES module GET Mozilla/5.0 (compatible; xAI-SearchBot/1.0; +https://x.ai)
request headers (8) 
{
  "accept-encoding": "gzip",
  "host": "uatracer.com",
  "traceparent": "00-c81a6394f951c29671f86ec4e7e0e0bb-0843203f60ce3ce3-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (compatible; xAI-SearchBot/1.0; +https://x.ai)",
  "via": "HTTP/1.1 ams.vultr.prod.deno-cluster.net",
  "x-deno-userspace-traceparent": "00-c81a6394f951c29671f86ec4e7e0e0bb-debc536cc2481fab-01",
  "x-deno-userspace-tracestate": ""
}
2026-07-02 12:55:19.534 UTC +3206 ms web app manifest GET Mozilla/5.0 (compatible; PerplexityBot/1.0; +https://perplexity.ai/perplexitybot)
request headers (8) 
{
  "accept-encoding": "gzip",
  "host": "uatracer.com",
  "traceparent": "00-8fe7a95e24ce68292ac8ed332742f911-428c768de56e6f68-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (compatible; PerplexityBot/1.0; +https://perplexity.ai/perplexitybot)",
  "via": "HTTP/1.1 ams.vultr.prod.deno-cluster.net",
  "x-deno-userspace-traceparent": "00-8fe7a95e24ce68292ac8ed332742f911-cc54697bb0d16191-01",
  "x-deno-userspace-tracestate": ""
}