DevTools

Generate a HAR file in Chrome (Safely)

A HAR file is a JSON archive of your browser’s HTTP requests and responses. It’s the fastest way to turn a real user workflow into a runnable API Flow in DevTools.

Follow these steps to avoid empty files, missing bodies, or noisy domains.

What a HAR contains (and why to be careful)

HAR files can include:

  • URLs, methods, headers, bodies
  • Responses, cookies, timing data

This can contain secrets and personal data. Use a test account and a safe environment; only capture what you need.

Before you start

  • Use a staging environment or a throwaway account
  • Close unrelated tabs (reduce noise)
  • Need request bodies? Enable “HAR with sensitive data” and export “with content” (steps below)

Record the HAR in Chrome

1

Open Chrome DevTools → Network

  • Right click → Inspect
  • Open the Network panel
2

Enable export with sensitive data (if you need bodies)

  • Network toolbar → gear icon
  • Preferences → Network → Allow to generate HAR with sensitive data
3

Capture the workflow

  • Check Preserve log (keeps requests across navigation)
  • Optional: Disable cache
  • Click the clear icon to start clean
  • Perform the workflow (login, click, submit, etc.)
4

Export the HAR with content

  • Toolbar download icon → Export HAR (with sensitive data)
  • Or right‑click request list → Save all as HAR with content

Suggested names: login-create-order.har, checkout-flow.har

Sanity check your HAR

Open the file and confirm:

  • File size isn’t 0 bytes
  • Includes log and entries

If it’s empty or missing bodies, re‑export with content/sensitive data enabled.

Import into DevTools Studio

Import the HAR

  1. Open DevTools Studio → Import → HAR File
  2. Select your .har

Filter and map domains

Remove analytics/fonts/CDNs; map domains to variables (e.g., BASE_URL).

Turn traffic into a reusable test

Review flow + dependencies

Check the generated sequence and auto‑detected variable chaining.

Replace secrets with env vars

Use environment variables like {{#env:API_TOKEN}} and {{#env:LOGIN_PASSWORD}}.

Export YAML and commit

Run once locally, then export to YAML and commit to your repo.

Troubleshooting

My HAR is empty / missing request bodies

  • Enable “Allow to generate HAR with sensitive data”
  • Export via “Save all as HAR with content”

My HAR has 1000+ requests

  • Clear the log before recording; close other tabs
  • Filter domains during import

No dependencies were detected

  • Detection is strongest when responses are JSON and values are reused later
  • For opaque tokens, map a variable once manually

Next steps