Web Security Headers & CSP Checker
Security Network on demand
HAR Network & Performance Analyzer
Local HAR analysisInspect request waterfalls, bottlenecks, payloads, caching, failures, and before/after captures locally.
How to use it
- 01
Open a network capture
Export a HAR from browser DevTools and open it locally; no capture is uploaded or replayed.
- 02
Find the bottleneck
Filter requests, inspect phase timings and headers, and review errors, redirects, slow TTFB, large transfers, caching gaps, duplicates, and HTTP URLs.
- 03
Compare and share safely
Compare two captures, copy a redacted cURL command, or export a sanitized HAR and CSV report.
Frequently asked questions
What is a HAR file?
HAR is a JSON-based archive of browser network requests, responses, headers, timings, and optional bodies. Its exact contents depend on the exporter.
Can a HAR contain secrets?
Yes. It may contain URLs, authorization headers, cookies, request bodies, and response data. Review even a sanitized export before sharing it.
Does the waterfall equal Core Web Vitals?
No. HAR timings explain network activity but do not contain complete field or rendering metrics such as LCP, INP, and CLS.
Are requests replayed?
No. Opening, filtering, diagnosing, comparing, and exporting a HAR are local read-only operations. Only copied cURL text can be run elsewhere by you.
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