ua-tracer by Paul Kinlan

trace U4cEcPZI

ua-tracer

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

← all traces

Trace U4cEcPZI

First seen: 2026-10-07 06:39:14.074 UTC
User-Agent: Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)
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
2026-10-07 06:39:14.074 UTC +0 ms homepage GET Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)
request headers (14) 
{
  "accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/heif,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7",
  "accept-encoding": "gzip, deflate, br, zstd",
  "accept-language": "zh,zh-CN;q=0.9",
  "host": "uatracer.com",
  "priority": "u=0, i",
  "sec-fetch-dest": "document",
  "sec-fetch-mode": "navigate",
  "sec-fetch-site": "none",
  "sec-fetch-user": "?1",
  "traceparent": "00-886549f882303cbcda9a80ea65ac9f2d-eaaecf83c6f2f7b1-01",
  "tracestate": "",
  "upgrade-insecure-requests": "1",
  "user-agent": "Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net"
}
2026-10-07 06:39:17.667 UTC +3593 ms CSS GET Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)
request headers (14) 
{
  "accept": "text/css,*/*;q=0.1",
  "accept-encoding": "gzip, deflate, br, zstd",
  "accept-language": "zh,zh-CN;q=0.9",
  "cookie": "[redacted]",
  "host": "uatracer.com",
  "priority": "u=0",
  "referer": "https://uatracer.com/",
  "sec-fetch-dest": "style",
  "sec-fetch-mode": "no-cors",
  "sec-fetch-site": "same-origin",
  "traceparent": "00-3d4411827445005522a9b7171dc88150-90d129b9985eb6cc-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net"
}
2026-10-07 06:39:17.686 UTC +3612 ms preload (image) GET Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)
request headers (15) 
{
  "accept": "image/heif,image/avif,image/webp,image/apng,image/svg+xml,image/*,*/*;q=0.8",
  "accept-encoding": "identity",
  "accept-language": "zh,zh-CN;q=0.9",
  "cookie": "[redacted]",
  "host": "uatracer.com",
  "priority": "i",
  "range": "bytes=0-499",
  "referer": "https://uatracer.com/",
  "sec-fetch-dest": "image",
  "sec-fetch-mode": "no-cors",
  "sec-fetch-site": "same-origin",
  "traceparent": "00-ef14a1bcf5972f72e7c2058321a342d0-8c3a352c3a4d3b4f-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net"
}
2026-10-07 06:39:17.885 UTC +3811 ms iframe document GET Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)
request headers (15) 
{
  "accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/heif,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7",
  "accept-encoding": "gzip, deflate, br, zstd",
  "accept-language": "zh,zh-CN;q=0.9",
  "cookie": "[redacted]",
  "host": "uatracer.com",
  "priority": "u=0, i",
  "referer": "https://uatracer.com/",
  "sec-fetch-dest": "iframe",
  "sec-fetch-mode": "navigate",
  "sec-fetch-site": "same-origin",
  "traceparent": "00-f0adf52de685cbe7f722e3fc27a1ccaa-e4758c78370350f1-01",
  "tracestate": "",
  "upgrade-insecure-requests": "1",
  "user-agent": "Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net"
}
2026-10-07 06:39:17.887 UTC +3813 ms image GET Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)
request headers (15) 
{
  "accept": "image/heif,image/avif,image/webp,image/apng,image/svg+xml,image/*,*/*;q=0.8",
  "accept-encoding": "identity",
  "accept-language": "zh,zh-CN;q=0.9",
  "cookie": "[redacted]",
  "host": "uatracer.com",
  "priority": "i",
  "range": "bytes=0-499",
  "referer": "https://uatracer.com/",
  "sec-fetch-dest": "image",
  "sec-fetch-mode": "no-cors",
  "sec-fetch-site": "same-origin",
  "traceparent": "00-7abad653e87a898e7d25f72a576948e5-a70caf7981fbd4b2-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net"
}
2026-10-07 06:39:17.892 UTC +3818 ms JS GET Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)
request headers (14) 
{
  "accept": "*/*",
  "accept-encoding": "gzip, deflate, br, zstd",
  "accept-language": "zh,zh-CN;q=0.9",
  "cookie": "[redacted]",
  "host": "uatracer.com",
  "priority": "u=1",
  "referer": "https://uatracer.com/",
  "sec-fetch-dest": "script",
  "sec-fetch-mode": "no-cors",
  "sec-fetch-site": "same-origin",
  "traceparent": "00-101f56b99ecb331771c4c264ed87fe87-dfe022d27cc8b8df-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net"
}
2026-10-07 06:39:17.967 UTC +3893 ms ES module GET Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)
request headers (15) 
{
  "accept": "*/*",
  "accept-encoding": "gzip, deflate, br, zstd",
  "accept-language": "zh,zh-CN;q=0.9",
  "cookie": "[redacted]",
  "host": "uatracer.com",
  "origin": "https://uatracer.com",
  "priority": "u=1",
  "referer": "https://uatracer.com/",
  "sec-fetch-dest": "script",
  "sec-fetch-mode": "cors",
  "sec-fetch-site": "same-origin",
  "traceparent": "00-7619ffa6272c2d8f63340db0a2d7ce40-eb4500539972a7b4-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net"
}
2026-10-07 06:39:18.765 UTC +4691 ms CSS @import (nested stylesheet) GET Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)
request headers (14) 
{
  "accept": "text/css,*/*;q=0.1",
  "accept-encoding": "gzip, deflate, br, zstd",
  "accept-language": "zh,zh-CN;q=0.9",
  "cookie": "[redacted]",
  "host": "uatracer.com",
  "priority": "u=0",
  "referer": "https://uatracer.com/r/U4cEcPZI/hfD7Qkn3/style.css",
  "sec-fetch-dest": "style",
  "sec-fetch-mode": "no-cors",
  "sec-fetch-site": "same-origin",
  "traceparent": "00-f655fb7fbbfccdeeedff79429078bb79-74e217ef0ace7dd4-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net"
}
2026-10-07 06:39:19.673 UTC +5599 ms image inside iframe GET Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)
request headers (15) 
{
  "accept": "image/heif,image/avif,image/webp,image/apng,image/svg+xml,image/*,*/*;q=0.8",
  "accept-encoding": "identity",
  "accept-language": "zh,zh-CN;q=0.9",
  "cookie": "[redacted]",
  "host": "uatracer.com",
  "priority": "i",
  "range": "bytes=0-499",
  "referer": "https://uatracer.com/r/U4cEcPZI/hfD7Qkn3/iframe",
  "sec-fetch-dest": "image",
  "sec-fetch-mode": "no-cors",
  "sec-fetch-site": "same-origin",
  "traceparent": "00-043548c1ecade527eea868a42b1387c7-f4ad54b3dbb48465-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net"
}
2026-10-07 06:39:20.198 UTC +6124 ms JS executed beacon GET Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)
request headers (15) 
{
  "accept": "image/heif,image/avif,image/webp,image/apng,image/svg+xml,image/*,*/*;q=0.8",
  "accept-encoding": "identity",
  "accept-language": "zh,zh-CN;q=0.9",
  "cookie": "[redacted]",
  "host": "uatracer.com",
  "priority": "i",
  "range": "bytes=0-499",
  "referer": "https://uatracer.com/",
  "sec-fetch-dest": "image",
  "sec-fetch-mode": "no-cors",
  "sec-fetch-site": "same-origin",
  "traceparent": "00-e60b68c8e6bf8a10aa6c28bfc831fca2-59523964cdd00de6-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net"
}
2026-10-07 06:39:20.290 UTC +6216 ms CSS background-image GET Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)
request headers (15) 
{
  "accept": "image/heif,image/avif,image/webp,image/apng,image/svg+xml,image/*,*/*;q=0.8",
  "accept-encoding": "identity",
  "accept-language": "zh,zh-CN;q=0.9",
  "cookie": "[redacted]",
  "host": "uatracer.com",
  "priority": "i",
  "range": "bytes=0-499",
  "referer": "https://uatracer.com/r/U4cEcPZI/hfD7Qkn3/style.css",
  "sec-fetch-dest": "image",
  "sec-fetch-mode": "no-cors",
  "sec-fetch-site": "same-origin",
  "traceparent": "00-1079ea81ceceb49b64db832bf6ab546e-36137731ef2df44a-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net"
}
2026-10-07 06:39:20.965 UTC +6891 ms ES module executed GET Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)
request headers (15) 
{
  "accept": "image/heif,image/avif,image/webp,image/apng,image/svg+xml,image/*,*/*;q=0.8",
  "accept-encoding": "identity",
  "accept-language": "zh,zh-CN;q=0.9",
  "cookie": "[redacted]",
  "host": "uatracer.com",
  "priority": "i",
  "range": "bytes=0-499",
  "referer": "https://uatracer.com/",
  "sec-fetch-dest": "image",
  "sec-fetch-mode": "no-cors",
  "sec-fetch-site": "same-origin",
  "traceparent": "00-b70ca2720d98db8f2ff8a9785bfaa127-c63909e9912573fb-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (Linux; Android 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Mobile Safari/537.36 (compatible; Bytespider; https://zhanzhang.toutiao.com/)",
  "via": "HTTP/2 ams.vultr.prod.deno-cluster.net"
}
2026-10-09 23:06:57.483 UTC +232063409 ms iframe document GET Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Amazonbot/0.1; +https://developer.amazon.com/support/amazonbot) Chrome/119.0.6045.214 Safari/537.36
request headers (9) 
{
  "accept-encoding": "gzip,deflate",
  "connection": "close",
  "host": "uatracer.com",
  "traceparent": "00-d4043b1f2e633efb331bace45782c89d-275906d89fef10dc-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Amazonbot/0.1; +https://developer.amazon.com/support/amazonbot) Chrome/119.0.6045.214 Safari/537.36",
  "via": "HTTP/1.1 ord.vultr.prod.deno-cluster.net",
  "x-deno-userspace-traceparent": "00-d4043b1f2e633efb331bace45782c89d-d4695f93aa9655de-01",
  "x-deno-userspace-tracestate": ""
}
2026-10-09 23:06:58.567 UTC +232064493 ms image inside iframe GET Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Amazonbot/0.1; +https://developer.amazon.com/support/amazonbot) Chrome/119.0.6045.214 Safari/537.36
request headers (9) 
{
  "accept-encoding": "gzip,deflate",
  "connection": "close",
  "host": "uatracer.com",
  "traceparent": "00-b43b068a1f1f29659663b9616470ec84-98cf5c575ea6af05-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Amazonbot/0.1; +https://developer.amazon.com/support/amazonbot) Chrome/119.0.6045.214 Safari/537.36",
  "via": "HTTP/1.1 ord.vultr.prod.deno-cluster.net",
  "x-deno-userspace-traceparent": "00-b43b068a1f1f29659663b9616470ec84-2b5f27706e46a898-01",
  "x-deno-userspace-tracestate": ""
}
2026-10-10 01:19:23.759 UTC +240009685 ms image inside iframe GET Mozilla/5.0 (compatible; crawler)
request headers (11) 
{
  "accept": "*/*",
  "accept-encoding": "gzip, deflate",
  "accept-language": "en-US",
  "connection": "keep-alive",
  "host": "uatracer.com",
  "traceparent": "00-d327b3cee03424596ebd122c6884f5dd-8ec9f14812b07815-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (compatible; crawler)",
  "via": "HTTP/1.1 ord.vultr.prod.deno-cluster.net",
  "x-deno-userspace-traceparent": "00-d327b3cee03424596ebd122c6884f5dd-934eb620fc089a5a-01",
  "x-deno-userspace-tracestate": ""
}
2026-10-10 01:40:31.263 UTC +241277189 ms image GET Mozilla/5.0 (compatible; crawler)
request headers (11) 
{
  "accept": "*/*",
  "accept-encoding": "gzip, deflate",
  "accept-language": "en-US",
  "connection": "keep-alive",
  "host": "uatracer.com",
  "traceparent": "00-7e199f90c2f437e3ccf66a562d0445db-af0e707e1a0c862b-01",
  "tracestate": "",
  "user-agent": "Mozilla/5.0 (compatible; crawler)",
  "via": "HTTP/1.1 ord.vultr.prod.deno-cluster.net",
  "x-deno-userspace-traceparent": "00-7e199f90c2f437e3ccf66a562d0445db-a7e2b3983cf2b4ad-01",
  "x-deno-userspace-tracestate": ""
}
2026-10-23 07:14:23.768 UTC +1384509694 ms iframe document GET Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Reflectionbot/1.0; +https://reflection.ai/bot) Chrome/151.0.0.0 Safari/537.36
request headers (13) 
{
  "accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8",
  "accept-encoding": "gzip,deflate,br",
  "accept-language": "en-US,en;q=0.9",
  "host": "uatracer.com",
  "sec-fetch-dest": "document",
  "sec-fetch-mode": "navigate",
  "sec-fetch-site": "none",
  "sec-fetch-user": "?1",
  "traceparent": "00-0eb5fa1271598480679a1816a18bcfab-7782cbf4d7992819-01",
  "tracestate": "",
  "upgrade-insecure-requests": "1",
  "user-agent": "Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Reflectionbot/1.0; +https://reflection.ai/bot) Chrome/151.0.0.0 Safari/537.36",
  "via": "HTTP/2 ord.vultr.prod.deno-cluster.net"
}

Client-side resource waterfall

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