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Overview

HTTP Status Code Explorer

Search common HTTP status codes, compare confusing client and server failures, and keep a sharper API debugging checklist in the browser.

Category hub

Web

Problems

5

FAQ

3

API Debugging Companion

HTTP Status Code Explorer

Search common HTTP status codes, compare lookalike failures such as 401 vs 403 vs 422, and keep a sharper debugging checklist next to the raw response you are investigating.

Tracked Codes
17
4xx Focus
7
5xx Focus
4
Find a status code
7 matches

401 Unauthorized

4xx

Authentication is missing, expired, or invalid for this request.

Common production scenario

The token is absent, malformed, expired, signed for the wrong audience, or dropped by a proxy.

What to check next
  • Confirm the Authorization header is actually reaching the server.
  • Check token expiry, issuer, audience, and environment-specific secrets.
Often confused with

What you can solve

What is the difference between 401 and 403?

A `401 Unauthorized` response usually means the authentication material itself is missing, expired, malformed, or otherwise unacceptable. A `403 Forbidden` response usually means the caller is authenticated but lacks the permissions, scope, plan, or ownership needed for that action.

How should I think about 400 versus 422 in API debugging?

Treat `400 Bad Request` as a signal that the server could not correctly parse or interpret the request structure at all. Treat `422 Unprocessable Entity` as a signal that the structure was valid enough to parse, but the payload failed validation or domain rules after parsing.

How do I separate a 429 problem from a 503 problem?

A `429 Too Many Requests` response points you first toward rate limits, quotas, and retry behavior. A `503 Service Unavailable` response points you toward temporary service instability, dependency strain, maintenance windows, or broader platform saturation.

What should I check first when I see an HTTP status code in a failing API request?

Start by separating client-side failure families such as `4xx` from server-side failure families such as `5xx`, because that changes the investigation path immediately. Then narrow the problem by asking whether you are dealing with syntax, auth, permissions, validation, throttling, or unstable upstream services.

How can I share a useful HTTP status code summary during an incident?

Share more than the official definition. Include the likely production scenario and the next checks your team should make, because that keeps everyone on the same debugging branch instead of arguing over a bare status code number.

Typical workflow

Guides for this workflow

Supporting guides that connect this tool to the broader category workflow.

Open category hub

What is

What is HTTP Status Code Explorer?

An HTTP Status Code Explorer helps you turn raw API failures into a more useful debugging sequence. Instead of treating status codes as a static reference table, you can compare common lookalikes such as `401` vs `403`, `400` vs `422`, or `429` vs `503` while keeping the next checks close at hand.

This is especially helpful during incident response and day-to-day API debugging, where a single code often sends teams down the wrong branch. A status explorer reduces that drift by pairing each code with a realistic production scenario and a shorter checklist for what to inspect next.

How to use

How to use HTTP Status Code Explorer

Search by code, title, or symptom such as `timeout`, `forbidden`, or `validation`, then narrow the list with the `2xx`, `3xx`, `4xx`, and `5xx` filters. Select a status to view its meaning, a realistic production scenario, the next checks to make, and nearby codes that are commonly confused with it.

When you want to share the result with a teammate, use `Copy summary` to capture a compact explanation and checklist for tickets, Slack threads, or handoff notes.

Example

Example

Example:
An API login call returns 401 in staging but 403 in production.

How to use the tool:
1. Open 401 and verify missing header, token expiry, issuer, or audience problems.
2. Compare 403 and check whether the token is valid but the role or scope is insufficient.
3. Copy the summary so the team aligns on whether this is an authentication problem or an authorization problem.

Common use cases

Common use cases

1. Comparing `401`, `403`, and `404` before changing auth logic blindly.

2. Distinguishing malformed requests (`400`) from validation failures (`422`).

3. Separating rate-limit incidents (`429`) from temporary service degradation (`503`).

4. Building faster incident notes during API outage triage.

Frequently asked questions

Frequently asked questions

How is this different from a normal HTTP status code chart?v
A chart gives you definitions, but it rarely tells you what engineers actually confuse in production. This explorer adds realistic scenarios, practical checks, and nearby codes that often trigger the wrong debugging branch.
Does this tool inspect a live response body?v
No. It is focused on code interpretation and triage guidance, not payload parsing. Pair it with tools such as JSON Validator when the response body itself may also be malformed.
Is it useful for backend teams as well as frontend teams?v
Yes. Frontend teams use it to reason about network failures quickly, while backend teams can use it as a fast checklist for support tickets, incident notes, and API review conversations.