PayloadScope — JSON & API Response Inspector

JSON viewer, network inspector & response diff for DevTools. Safe cURL export with auto-redacted credentials. 100% local.

PayloadScope is a JSON viewer and API response inspector built directly into Chrome DevTools — a dedicated panel next to Console and Network that captures, formats, searches, and diffs JSON from your app's API calls, with safer cURL export than copy-pasting raw requests. The problem this solves: Debugging an API today usually means jumping between tools: the Network tab to find the request, a separate online JSON formatter to actually read the response, a text editor to compare two payloads by eye, and a manual scrub of any cURL command before you dare paste it into a bug report or Slack thread. PayloadScope collapses all of that into one panel that's already open while you're debugging. JSON formatting that actually handles real-world APIs: Most JSON viewers assume a response is clean JSON and stop there. Real APIs are messier: event-logging endpoints, GraphQL responses, and webhook payloads frequently nest JSON as an escaped string inside the outer object, which shows up as an unreadable wall of backslashes in most tools. PayloadScope detects this pattern and recursively expands it, so nested data renders as real, readable structure instead of escaped text — no copy-pasting into a second tool just to make sense of it. Search within any response: Stop scrolling through a giant payload looking for one field. Type a key or value and PayloadScope highlights every match instantly, right in the formatted view. Pin and diff two responses side by side: Suspect an API response changed between two calls, or want to compare a passing case against a failing one? Pin any two requests and PayloadScope shows a line-level diff, with additions and removals color-coded, so you can spot exactly what's different without manually comparing two JSON blobs. Network inspector basics, done well: Every XHR and fetch request the page makes shows up automatically with method, status code, response time, and size — filterable by status range (2xx, 4xx, 5xx, or both error ranges at once) so you can jump straight to what's failing. A "Preserve log" toggle, matching the one in Chrome's own Network tab, keeps your capture history intact across page reloads instead of losing context every time you navigate. cURL export that doesn't leak your session by default: Copying a request as cURL is a common way to share what's happening with a teammate or paste into a bug report — but doing that with a real authenticated request usually means copying live cookies, auth headers, and session tokens in plain text along with it. PayloadScope redacts cookies, authorization headers, API keys, session IDs, and CSRF tokens by default when you copy as cURL, with a clearly separate "include credentials" option (plus a confirmation step) for when you genuinely need the full runnable command. This applies to credentials hiding inside the request body too, not just headers. 100% local — nothing leaves your browser: PayloadScope makes no network requests of its own, sends no data anywhere, and stores nothing outside your current DevTools session. It reads network activity through Chrome's own devtools API — the same data your Network tab already shows you — and nothing more. No analytics, no tracking, no third-party calls. Built for developers who debug real production and staging APIs day to day: frontend engineers tracking down why a response looks wrong, backend engineers verifying their own endpoints, and QA engineers comparing expected versus actual payloads. If you've ever pasted an API response into an online JSON formatter just to read it, or manually scrubbed a cURL command before sharing it, PayloadScope replaces both habits with one panel that's already open. Common questions: Does it work with GraphQL? Yes — GraphQL responses are standard JSON over HTTP, so they're captured and formatted like any other API call, including the nested-string-JSON pattern GraphQL APIs often use. Does it require a backend or account? No. There's nothing to sign up for and no server involved. Install it and it works immediately on any site you're already debugging. Is it free? Yes, the core JSON viewer, search, network inspector, and redacted cURL export are free. A Pro tier with pin/diff and credential-included export is planned but not yet available for purchase. Does it replace Postman? No — Postman is for constructing and sending your own requests. PayloadScope is for inspecting traffic your app already generates while you use it normally, with no separate request-building step.