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Resource waterfall analyzer

Drop in a HAR file or paste its JSON and see every request as a timed waterfall split into DNS, connect, TLS, wait, and download phases, with findings and a CSV export.
Drop a .har file or paste its JSON. The waterfall shows every request split into queueing, DNS, connect, TLS, send, wait, and download, with markers for DOMContentLoaded and load.

Phases follow the HAR 1.2 timing model: TLS sits inside the connect segment rather than being counted twice, and a negative timing means the phase did not happen. Render-blocking candidates are candidates only, because a HAR cannot show the async or defer attributes. This tool reads a capture that already happened; it does not fetch anything, so it cannot measure a live page.
Options

More web & auth tools

- HTTP timing probe (/network/http-timing)
- HTTP header parser (/web/headers)
- CSP evaluator & builder (/web/csp)
All web & auth tools (/web)

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Canonical HTML: https://nutter.tools/web/resource-waterfall-analyzer
Markdown version: https://nutter.tools/web/resource-waterfall-analyzer.md
Plain-text version: https://nutter.tools/web/resource-waterfall-analyzer.txt
Agent index: https://nutter.tools/llms.txt