How HTTP Works

Tools

HTTP Tools

Free interactive tools for learning, building, and debugging HTTP. No sign-up required — everything runs in your browser.

What does this request look like on the wire?

HTTP Playground

Compose requests, inspect responses, explore headers, cookies, and raw HTTP wire format.

Which headers does this URL send, and are they safe?

Header Inspector

Fetch any URL and analyze its response headers with security grading.

Where does this URL actually end up?

Redirect & Canonical Auditor

Follow redirect chains, inspect canonicals, and catch noindex or indexing conflicts.

Why was my cross-origin request blocked?

CORS Debugger

Simulate cross-origin requests to see if they pass or fail — with preflight visualization.

Which Cache-Control header do I need?

Cache-Control Builder

Toggle caching directives and get the generated header with plain-English explanation.

How do I set this cookie safely?

Set-Cookie Builder

Compose Set-Cookie headers visually with security attributes and expiry settings.

Which status code should I return?

Status Code Picker

Answer a few questions to find the right HTTP status code for your API response.

What does this raw HTTP message mean?

HTTP Message Parser

Paste raw HTTP and see it parsed with color coding and hover explanations.

Does my Content-Security-Policy actually protect anything?

CSP Evaluator & Builder

Paste a Content-Security-Policy to grade it, or build a strict nonce or hash policy with server snippets.

What request will this curl command send?

curl Command Explainer

Explain every flag, see the exact HTTP request, and convert to fetch or Python requests.

Is this site configured securely?

Site Verifier

Scan any URL for SSL/TLS validity, security headers, cookie safety, and caching analysis.

Choose A Starting Workflow

If you are not sure which tool to open first, pick the workflow that matches the problem you are actually trying to solve.

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