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tools / node-performance

Node Performance Analyzer

Analyze Node.js event-loop lag, CPU profiles, heap pressure, async bottlenecks, and server timing evidence.

P2PerformanceHigh severity
100
debug signal score
4 signals

4 signals detected. Start with event-loop lag.

Detected signals

Event-loop lag

The Node event loop may be blocked.

Find synchronous CPU work, large JSON serialization, crypto, compression, or blocking filesystem calls.

Heap pressure

Node memory pressure is present.

Capture heap snapshots and check caches, queues, and retained request data.

CPU hotspot

CPU profiling data is available.

Sort by self time and verify optimization with another profile.

Endpoint timeout

A request exceeded its time budget.

Trace downstream calls, queueing, and serialization for the endpoint.

Highlighted lines
line 1
event loop delay p99=420ms
Event-loop lag
line 2
heapUsed=900MB
Heap pressure
line 3
CPU profile hot function serializeResponse
CPU hotspot
line 4
GET /api/report 504 timeout
Endpoint timeout
Fix checklist
Find synchronous CPU work, large JSON serialization, crypto, compression, or blocking filesystem calls.
Capture heap snapshots and check caches, queues, and retained request data.
Sort by self time and verify optimization with another profile.
Trace downstream calls, queueing, and serialization for the endpoint.
Measure event-loop delay and CPU separately.
Check heap and queue depth over time.
Reproduce with production-like payload size.

DebugTools product

Node Performance Analyzer

Node Performance Analyzer is a focused DebugTools mini-product for developers. Analyze Node.js event-loop lag, CPU profiles, heap pressure, async bottlenecks, and server timing evidence.

Use cases

  • Identify slow paths, hot operations, large bundles, and runtime bottlenecks.
  • Compare before/after evidence while tuning performance.
  • Summarize profiler output into follow-up actions.

How it works

  • Paste or load the snippet you want to inspect in Node Performance Analyzer.
  • Run the tool in the browser and review the highlighted output.
  • Copy, export, or turn the result into the next debugging step.

Privacy

  • Node Performance Analyzer is local-first. The core workflow runs in your browser and does not require sending pasted content to DebugTools servers.

This tool history

Recent Node Performance sessions

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