Playwright-powered

Browser monitoring with dependency intelligenceSee what's breaking — and what's causing it

Browser checks that go beyond pass/fail. Third-party domains attributed, Web Vitals anomaly-scored, and every step captured — all flowing into your OTel backend as a rich insight pack.

cross-monitor dependency view
MonitorLCP3P Impact
Checkout Flow3.2s+2.1σ
Product Detail2.9s+1.8σ
Homepage3.6s+2.4σ
Search Results2.7s+1.3σ
Shared dependency detected
cdn.tagmanager.net · 4 monitors · never deployed

How it works

01

Playwright runs in a real browser

Your script runs in a real Chromium instance in an isolated container on a global location. No headless shortcuts — full browser, full network stack, real third-party requests.

02

Every request classified and attributed

Third-party requests classified by domain. Payload bytes, request latency, and blocking vs non-blocking measured per domain, per check run, and across your monitor portfolio.

03

OTel insight pack emitted

Web Vitals, anomaly scores, dependency attribution, correlation signals, filmstrip screenshot URLs, and W3C traceparent — all emitted as a single OTLP insight pack to your backend.

Third-party attribution, automatic

Every request hostname compared to the page hostname. Domain, payload bytes, and request latency tracked per-check and across your monitor portfolio. When a tag manager script starts behaving differently, you know which monitors are affected — before users file support tickets.

  • Third-party domains identified and classified automatically
  • Payload bytes tracked per domain per run
  • Cross-monitor shared dependency detection
  • Anomaly scored against per-domain baselines
  • Emitted as structured OTel span attributes
Third-party domains on Checkout Flow
cdn.tagmanager.net
847 KB324ms
analytics.google.com
42 KB89ms
fonts.googleapis.com
12 KB31ms
cdn.stripe.com
156 KB78ms
Screenshot URLs in OTel spans
Step 1 — Page load
0msscreenshot →
Step 2 — Login form
1,240msscreenshot →
Step 3 — Product added
2,890msscreenshot →
Step 4 — Checkout
4,120msscreenshot →
URLs embedded in OTLP spans — accessible from any tool in your stack

Filmstrip evidence

Every step in your Playwright script captured and stored. Screenshot URLs embedded directly in OTel spans. Pull up the filmstrip from inside Grafana or your incident runbook — no context switch to a separate monitoring dashboard required.

When your checkout breaks at 2am, the on-call engineer opens the alert, clicks the screenshot URL in the span, and sees exactly what the user saw — in the same tool they already have open.

Web Vitals, anomaly-scored

LCP, FCP, CLS, and TTFB tracked against 14-day rolling baselines, calculated per location and per hour of day. Deviation in σ emitted in every span — your backend knows "+2.1σ on LCP from Tokyo at 14:00 UTC", not just a raw number.

No fixed thresholds to maintain. No manual tuning when your app ships a performance improvement. The baseline adapts — and alerts fire when behavior deviates from what's normal for that check, that location, and that time of day.

Web Vitals — Checkout Flow / Tokyo
LCP+2.1σ
Current: 3.2sBaseline: 1.4s
FCP+0.4σ
Current: 1.1sBaseline: 0.9s
CLS+0.6σ
Current: 0.02Baseline: 0.01
TTFB+1.2σ
Current: 420msBaseline: 280ms

Unlike isolated browser check runners

  • Most tools run browser checks in isolation. Yorker tracks third-party domains across your entire monitor portfolio — a failing CDN shows up across all affected monitors simultaneously, not as four separate unrelated alerts.

  • Filmstrip screenshots are stored and linked in OTel spans, not locked in a proprietary dashboard. Pull them up from any tool in your stack — Grafana, a PagerDuty runbook, or a Slack alert.

  • Web Vitals are anomaly-scored against per-location, per-hour-of-day baselines — not compared to a fixed threshold you have to maintain and tune as your app evolves.

Close your observability blind spot

Free tier includes 10,000 HTTP checks and 1,500 browser checks per month. No credit card required.

npx yorker init