HAR Export & Import

NectoProxy supports the HTTP Archive (HAR) format for exporting and importing captured traffic. HAR is an industry-standard JSON format that lets you share captured network data with teammates, import it into other tools, and create persistent records of debugging sessions.

What is HAR?

The HTTP Archive (HAR) format is a JSON-based specification for recording HTTP transactions. It was originally developed for the HTTP Archive project and has since become the standard interchange format for HTTP debugging tools.

NectoProxy implements HAR 1.2, the latest version of the specification. A HAR file contains:

• Complete request details (method, URL, headers, body, cookies)
• Complete response details (status, headers, body, content)
• Timing information (DNS, connect, TLS, send, wait, receive)
• Page and entry metadata
• Creator and browser information

HAR 1.2 Structure Overview

{
  "log": {
    "version": "1.2",
    "creator": {
      "name": "NectoProxy",
      "version": "1.0.0"
    },
    "entries": [
      {
        "startedDateTime": "2025-01-15T10:30:00.000Z",
        "time": 245,
        "request": {
          "method": "GET",
          "url": "https://api.example.com/v1/users",
          "httpVersion": "HTTP/1.1",
          "headers": [...],
          "queryString": [...],
          "cookies": [...],
          "headersSize": 320,
          "bodySize": 0
        },
        "response": {
          "status": 200,
          "statusText": "OK",
          "httpVersion": "HTTP/1.1",
          "headers": [...],
          "cookies": [...],
          "content": {
            "size": 1234,
            "mimeType": "application/json",
            "text": "{...}"
          },
          "headersSize": 250,
          "bodySize": 1234
        },
        "timings": {
          "dns": 12,
          "connect": 35,
          "ssl": 48,
          "send": 1,
          "wait": 132,
          "receive": 17
        }
      }
    ]
  }
}

Exporting to HAR

Exporting a Full Session

Export all traffic in the current session to a single HAR file:

1. Open the Export menu in the NectoProxy toolbar
2. Select Export Session as HAR
3. Choose a filename and save location
4. The HAR file is generated and downloaded

The exported file includes every request/response pair captured in the current session, with full headers, bodies, and timing data.

Exporting Selected Entries

Export only specific traffic entries:

1. Select the entries you want to export in the traffic list (use Ctrl+Click or Shift+Click for multi-select)
2. Right-click and choose Export Selected as HAR, or use the Export menu
3. The HAR file contains only the selected entries

TIP

Exporting selected entries is useful when you want to share a specific API call or a particular sequence of requests without including all the noise from a full session.

What is Included in the Export

Data	Included	Notes
Request method and URL	Yes	Full URL including query parameters
Request headers	Yes	All headers including cookies
Request body	Yes	For POST, PUT, PATCH requests
Response status	Yes	Status code and reason phrase
Response headers	Yes	All response headers
Response body	Yes	Full body content, decompressed
Timing data	Yes	DNS, connect, TLS, send, wait, receive
TLS information	Yes	Protocol version, cipher suite
WebSocket frames	Partial	Initial upgrade is included; individual frames are not part of HAR spec

Sensitive Data

HAR files contain all request and response data, including authorization headers, cookies, session tokens, and any sensitive information in request/response bodies. Review the content of HAR files before sharing them. Consider removing or redacting sensitive information.

Importing HAR Files

Importing a HAR File

Load traffic from a HAR file into NectoProxy for inspection:

1. Open the Import menu in the NectoProxy toolbar
2. Select Import HAR File
3. Choose the .har file from your filesystem
4. The imported entries appear in the traffic list

Imported entries are displayed in the traffic list just like live-captured traffic. You can inspect headers, bodies, timing information, and use all of NectoProxy's analysis features on the imported data.

HAR Validation

When importing a HAR file, NectoProxy validates the file structure against the HAR 1.2 specification:

• Valid HAR files are imported immediately
• HAR files with minor issues (e.g., missing optional fields) are imported with warnings
• Invalid or corrupt files are rejected with an error message describing the issue

Common Validation Issues

Issue	Severity	Resolution
Missing log.version	Warning	Defaults to "1.2"
Missing log.creator	Warning	Uses "Unknown" as creator
Missing entry.startedDateTime	Warning	Uses import timestamp
Invalid JSON syntax	Error	Fix the JSON syntax in the file
Missing log.entries array	Error	Ensure the file has the correct HAR structure
Empty entries array	Warning	File is valid but contains no traffic data

Sharing Captured Traffic

HAR files are the standard way to share captured network traffic with teammates or include in bug reports. Common sharing workflows include:

For Bug Reports

1. Capture the traffic that demonstrates the bug
2. Select the relevant entries
3. Export as HAR
4. Attach the HAR file to the bug report
5. The engineer investigating the bug can import it into NectoProxy (or any HAR-compatible tool) to inspect the exact traffic

For Code Reviews

When a code change affects API behavior, export the before/after traffic as HAR files and attach them to the pull request. Reviewers can import both files and use NectoProxy's Request Comparison feature to see the differences.

For Documentation

Export HAR files of expected API flows and include them in your API documentation or integration guides. These serve as executable examples that developers can import and inspect.

Integration with Other Tools

HAR is an open standard supported by many tools. NectoProxy's HAR files are compatible with:

Tool	Import	Export	Notes
Chrome DevTools	Yes	Yes	Network tab supports HAR import/export
Firefox DevTools	Yes	Yes	Network monitor supports HAR
Charles Proxy	Yes	Yes	Full HAR 1.2 support
Fiddler	Yes	Yes	Import and export HAR files
Postman	Yes	No	Import HAR as a collection
Insomnia	Yes	No	Import HAR files
har-analyzer	Yes	No	Online HAR analysis tool
WebPageTest	Yes	No	Analyze HAR for performance metrics

Cross-Tool Workflow

A common workflow is to capture traffic in Chrome DevTools, export as HAR, import into NectoProxy for advanced analysis (rules, breakpoints, replay), and then re-export for sharing. The HAR format ensures data fidelity across all these tools.

Practical Examples

Example 1: Debugging a Production Issue

A user reports that a specific API call is failing. To investigate:

1. Ask the user to export a HAR file from their browser's DevTools
2. Import the HAR file into NectoProxy
3. Inspect the failing request's headers, body, and timing
4. Use the information to reproduce and fix the issue locally

Example 2: Performance Baseline

Create a performance baseline for your application:

1. Open your application and navigate through key user flows
2. Export the full session as a HAR file
3. Save the HAR file as a baseline with a descriptive name (e.g., baseline-2025-01-15.har)
4. After making optimizations, repeat the process and compare timing data between the baseline and current HAR files

Example 3: API Regression Testing

Verify that a backend deployment has not changed API behavior:

1. Before the deployment, capture and export API traffic as a HAR file
2. After the deployment, replay the same requests using Request Replay
3. Export the replayed traffic as a new HAR file
4. Compare the two HAR files to identify any changes in response bodies, headers, or status codes

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INFO

HAR files can become large when capturing traffic with large response bodies (images, videos, large JSON payloads). NectoProxy includes response body content in exports by default. For large sessions, consider exporting only selected entries or using the session export options to exclude binary content.