Is my HAR file uploaded anywhere?

No. The file is read with the browser's FileReader and parsed in JavaScript on your machine. HAR files often contain cookies, auth tokens and request bodies, so keeping them local matters.

HAR (HTTP Archive) is a JSON format that browsers and proxies use to record a full session of HTTP requests and responses, including timing. DevTools can export one for debugging.

What do the timing phases mean?

Each entry has a timings object: blocked (queueing), dns (name lookup), connect (TCP), ssl (handshake), send (uploading the request), wait (server think time / TTFB), and receive (downloading the response).

Why are some timing values -1?

The HAR spec uses -1 to mean a phase was not applicable or not measured. For example a reused keep-alive connection has dns and connect set to -1 because no new connection was opened.

Can it show response bodies?

It shows whatever the HAR includes. If you exported without content the bodies are empty; with content they are stored under each entry's response.content.text and previewed here.

HAR File Viewer — Gera Tools

Read HAR files without a server

A HAR (HTTP Archive) file is the JSON your browser’s DevTools produces when you save a Network panel session. It captures every request and response — URLs, methods, status codes, headers, cookies, sizes and millisecond-level timings. This viewer parses that JSON entirely in your browser so you can analyse a performance trace or a bug report without pasting a file that may contain auth tokens into a remote service.

How it works

The tool reads the file with FileReader (or accepts pasted JSON) and runs JSON.parse. A valid HAR has a top-level log.entries array; each entry holds a request, a response, a time (total milliseconds) and a timings object. The viewer sums and displays the timing phases — blocked, dns, connect, ssl, send, wait and receive — which together make up the total. Phases reported as -1 mean “not applicable” (for example a reused connection skips dns and connect). Sizes come from response.content.size and the transfer bodySize. Sorting and filtering happen over the parsed array in memory.

Tips and notes

“Save all as HAR with content” includes response bodies; the plain export does not, which keeps the file smaller but hides payloads.
High wait (TTFB) points at slow server processing; high receive points at a large or slow download; high blocked means the request was queued behind others on the same connection.
HAR files frequently contain Authorization headers and Set-Cookie values — scrub them before sharing a HAR publicly.