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W3C Network Error Logging & Reporting API Telemetry

Last-Mile Browser Network Visibility. Zero JavaScript.

Direct telemetry into DNS lookup timeouts, TCP connection drops, TLS handshake failures, and origin 5xx spikes, reported natively by modern browser user agents without client-side JavaScript SDKs.

Or explore the interactive last-mile dashboard demo below
Account-Bound Multi-Domain GovernanceInstant Apex DNS TXT VerificationRFC 8941 Compliant
Live Interactive Telemetry DemoTarget: example.comIn-Memory Synchronous Engine

Production Edge Telemetry Console

Eliminating the "Pre-JS" Blind Spot across all Network Failure Phases: simulate real-world network failure scenarios, toggle time windows, filter across layers, and inspect out-of-band browser telemetry.

Simulate Failure Scenario Presets:Click any scenario to immediately recompute telemetry across all charts
Scenario Active: Edge TLS Certificate Expiry: Automated ACME renewal failed on edge proxy ingress. Browsers terminate handshakes immediately with tls.cert.date_invalid across all eyeball ASNs.
Layer / W3C Phase:
Authenticity Filter:

Network Reliability Posture

F
0%Critical Outage

Composite reliability index evaluating last-mile DNS, TCP / QUIC, TLS, and HTTP failure velocity.

Dominant Failure:TLS (73% of errors)

Total Failure Reports

535errors / 1d

Eyeball Transit Corroboration

6Autonomous Systems (ASNs)

Distinct client eyeball networks reporting connectivity dropouts to your origin endpoints.

Raw Reports Ingested
535

Failure Velocity Timeline

Nov 14, 12:30 to Nov 15, 11:30

Hourly failure report volume bucketed by W3C NEL resolution phase (peak: 27 / bucket).

Nov 14, 12:3017:3021:3002:3006:30Nov 15, 11:30

Failure Phase & Error Breakdown

Orthogonal W3C NEL phases (dns, connection, application) mapped across 4 transport & crypto layers.

8%
44
14%
75
73%
388
5%
28

Top Impacted Endpoints

Top Impacted Endpoints

Sanitized destination URLs experiencing browser failure reports across DNS, TCP / QUIC, TLS, and HTTP layers.

Sanitized Endpoint URLDominant LayerTop Error CodeFailure CountAffected ASNsLast IncidentInspect
https://example.com/api/v1/checkout
TLS (QUIC)phase: connection
16014 ASNs11:27 AM
https://example.com/auth/login
TLSphase: connection
13111 ASNs11:27 AM
https://example.com/assets/app.js
TLS (QUIC)phase: connection
978 ASNs11:27 AM
https://example.com/api/v2/telemetry
HTTPphase: application
747 ASNs11:27 AM
https://example.com/
DNSphase: dns
519 ASNs11:27 AM

Eyeball ASN Distribution

ISP Transit & Eyeball Network Analysis

Autonomous Systems encountering connectivity disruptions to distinguish single-carrier eyeball flaps from global origin outages.

Comcast Cable CommunicationsH3 / QUICH2
Top error: tls.cert.date_invalid
154
reports
AT&T Services, Inc.H2H3 / QUIC
Top error: tls.cert.date_invalid
97
reports
Deutsche Telekom AGH3 / QUICH2
Top error: tls.cert.date_invalid
74
reports
Free SAS (Iliad France)H2H3 / QUIC
Top error: dns.name_not_resolved
51
reports
Cloudflare, Inc.H3 / QUICH2HTTP/1.1
Top error: http.error.504
46
reports

Architectural Overview & Infrastructure Solutions

Deep-dive into the browser socket lifecycle, 4-phase failure invariants, and edge network use cases.

Pre-JS Blind Spot vs W3C NEL

Understand why client-side JavaScript SDKs cannot capture DNS lookup timeouts, TLS negotiation aborts, or edge 502 Bad Gateway responses.

Explore Browser Architecture

4-Phase Taxonomy & Playbooks

Triage DNS, TCP, TLS, and HTTP errors with protocol RFC invariants, authoritative server routing checks, and actionable SRE playbooks.

Review Taxonomy & Playbooks

Edge & Industry Solutions

Purpose-built network observability for Multi-CDN infrastructure, FinTech APIs, high-volume e-commerce, and enterprise B2B SaaS platforms.

View Infrastructure Solutions
Have custom edge infrastructure or enterprise SLA requirements? Contact engineering