HTTP Status Codes

📖 Tool Introduction

HTTP Status Codes is an offline reference tool built for web developers. When you debug an API, chase down a broken page or read through server logs, you often need to instantly understand what a number like 401, 403, 502 or 504 actually means and when it shows up. This tool gathers the most common response codes into cards, covering the five families: 1xx informational, 2xx success, 3xx redirection, 4xx client error and 5xx server error. Each card shows the three-digit number, the standard reason phrase and one short sentence describing a real-world scenario, for example that 429 means too many requests and rate limiting kicked in, that 304 means the resource was not modified and the cache may be used, and that 502 means the gateway received an invalid response from an upstream server. The search bar on top does fuzzy matching by number or by English name, so typing 404 or not found lands you on the right card, and the category tabs below let you narrow the list to a single family in one click. A colored badge in the corner of each card is tinted by family, so you can tell at a glance which kind of response you are looking at. All of the data is bundled into the page, which means the tool works with no network connection and stays useful on intranets or offline machines. The descriptions are available in Simplified Chinese, Traditional Chinese and English, and the layout adapts cleanly to both desktop and mobile screens, so you can look a code up whenever you hit it in a log or an error page. This matters during on-call incidents, when seconds count and you do not want to lose context by opening a heavyweight documentation site. Keeping the lookup instant and offline means the tool stays open in a tab alongside your debugging session without slowing anything down.

✨ Key Features

• Broad coverage: over thirty high-frequency codes from 1xx to 5xx are built in
• Instant search: fuzzy matching by numeric code or English reason phrase
• Category tabs: filter to informational, success, redirect, client or server errors
• Scenario notes: each code comes with a one-line real-world explanation
• Color badges: tinted by family so the response type is obvious at a glance
• Offline ready: all data is bundled, no network needed to look a code up

📝 How to Use

1. Type a numeric code or an English name into the top search box
2. The list filters live to show only the matching cards
3. Click a category tab to browse just that family of codes
4. Read the number, the reason phrase and the scenario note on each card
5. Clear the search box to return to the full list

⚠️ Notes

• Common subset: the list covers frequent codes, not the entire standard
• Search matching: search matches both the number and the English reason phrase
• Family rule: the first digit defines the family: 1xx info, 4xx client, 5xx server
• Offline use: all data is bundled and the tool works without a network
• For reference: exact semantics follow the RFCs and the real server implementation