How do I get a HAR file?

In Chrome or Edge DevTools, open the Network tab, reproduce the slow page load, then right-click a request and choose Save all as HAR. Firefox has Export HAR in its Network monitor.

Is my capture uploaded anywhere?

No. The file is read in the browser and analyzed locally. HAR files can contain cookies and tokens, so keeping them local matters.

What do the timing phases mean?

Blocked is queueing, DNS is name resolution, connect is the TCP/TLS handshake, send is uploading the request, wait is time to first byte, and receive is downloading the response.

How large a file can I analyze?

The first 2,000 entries are analyzed; larger captures are flagged as truncated so you know the totals are partial.

HAR analyzer

Drop a HAR capture, see where the time went.

Runs in browser

Use via MCP

Capture

Drop a .har fileor paste the JSON below · stays in this browser

HAR JSON

Analysis

No capture yet

Drop a .har file or paste HAR JSON to analyze it.

Drop a HAR file to begin

Use from your agent

Streamable HTTP at https://benchline.fabwaseem.com/mcp. No key. The tool name is analyze_har.

mcp.jsonjson

2 "mcpServers": {

3 "benchline": {

4 "url": "https://benchline.fabwaseem.com/mcp"

5 }

6 }

tools/calljson

2 "jsonrpc": "2.0",

3 "id": 1,

4 "method": "tools/call",

5 "params": {

6 "name": "analyze_har",

7 "arguments": {

8 "har": "example",

9 "top": 5

10 }

11 }

12}

Related tools

How it works

Free HAR file analyzer. Drop a .har capture or paste its JSON to get a request table with method, URL, status, size, and time, plus summary stats: totals, status-code distribution, the slowest requests, the largest payloads, top hosts, and a per-request timing breakdown of blocked, DNS, connect, send, wait, and receive.

01
Load the capture
Drop a .har file or paste the HAR JSON into the input pane.
02
Read the summary
Totals, status-code distribution, slowest requests, largest payloads, and top hosts appear first.
03
Inspect a request
Pick a row to see its timing breakdown across blocked, DNS, connect, send, wait, and receive.