Stop Pasting Sensitive API Payloads into Random Websites. Here’s a Better Way.

If you are an SDET or backend developer writing API tests, you know the drill: an endpoint returns a massive, unformatted JSON payload. To figure out why your RestAssured or Cucumber assertion failed, you copy the response, open a new tab, search for a JSON formatter, and paste it in.

Then you realize you just pasted customer data and internal authentication tokens into a random, ad-supported server.

I built Captain JSON under the Pirates of Bugs initiative to eliminate this exact workflow friction and keep your data strictly on your machine.

What is Captain JSON?
Captain JSON is a local-first browser extension designed specifically for the daily workflows of quality engineering specialists and API developers. It runs 100% offline, meaning your payloads never leave your browser.

Core Developer Features
JSONPath Generator & Evaluator: Stop guessing the path to a nested array element. Click any node in your JSON tree to instantly generate the exact JSONPath expression needed for your automation frameworks.

JSONL File Processing: Log files formatted in JSON Lines (JSONL) often crash standard text editors. Captain JSON processes and lets you inspect them smoothly right in the browser.

Side-by-Side Comparison: Paste two payloads to instantly highlight schema mismatches, missing keys, or altered values—crucial for regression testing endpoint updates.

Zero Server Transmission: The formatting, validation, and parsing happen entirely locally.

Stop Context-Switching
The goal is a single-tool workflow. You shouldn't need three different web utilities to format a payload, write a JSONPath, and compare environments.

You can grab the extension from the Chrome Web Store here: https://piratesofbugs.com/captain-json

Try it out on your next API test run, and let me know what features you want to see next as we expand the Pirates of Bugs toolset!