Introduction to 1xx Informational Status Codes– When a browser talks to a server, the server sends HTTP status codes. These codes tell the browser what’s happening. 1xx status codes are informational responses. They show that the server got the request and is still processing it.
These codes are not errors. Instead, they give updates before the final response. They are part of HTTP/1.1 and later versions.
Why Are 1xx Status Codes Important?
1xx informational status codes help in smooth communication. They let the client (browser) know the server is working. Without them, the browser might think the server is stuck.
These codes are rare in everyday browsing. But they are useful in advanced web applications and API communications.
Common 1xx Status Codes
Here are the most common 1xx HTTP status codes:
1. 100 Continue
- The server confirms it received the request headers.
- The client can now send the request body.
- Used in large file uploads to check if the server accepts the request.
2. 101 Switching Protocols
- The server agrees to change protocols (e.g., from HTTP to WebSocket).
- Common in real-time applications like chat systems.
3. 102 Processing (WebDAV)
- The server is still processing the request.
- Prevents timeouts for long-running operations.
- Used in WebDAV (Web Distributed Authoring and Versioning).
4. 103 Early Hints
- The server sends some headers before the full response.
- Helps browsers start loading resources early.
- Improves website performance.
How 1xx Status Codes Work
When a client sends a request, the server may reply with a 1xx code first. For example:
- The browser sends a request to upload a big file.
- The server responds with 100 Continue.
- The browser then sends the file data.
Without 100 Continue, the browser would send the whole file at once. This could waste bandwidth if the server rejects the request.
When Are 1xx Codes Used?
Most websites don’t show 1xx codes to users. But they are used in:
- Large file transfers (100 Continue).
- Real-time apps like gaming or chats (101 Switching Protocols).
- Optimized web performance (103 Early Hints).
Differences Between 1xx and Other Status Codes
- 1xx (Informational): Temporary updates before the final response.
- 2xx (Success): The request was successful (e.g., 200 OK).
- 3xx (Redirection): The client must take another action.
- 4xx (Client Errors): The request has an issue (e.g., 404 Not Found).
- 5xx (Server Errors): The server failed to complete the request.
How to Check 1xx Status Codes
Developers can see these codes using:
- Browser Developer Tools (Network Tab).
- Command-line tools like cURL.
- API testing tools like Postman.
Common Misconceptions About 1xx Codes
- They indicate errors: No, they are just updates.
- They are visible to users: Usually, only developers see them.
- All servers use them: Only some advanced applications need them.
Conclusion
1xx informational status codes play a key role in web communication. They ensure smooth data transfer between clients and servers. While not common in everyday browsing, they help in performance optimization and real-time systems.
Understanding these codes helps developers build faster and more reliable web applications.
Key Takeaways
- 1xx codes are temporary responses before the final result.
- 100 Continue helps in large uploads.
- 101 Switching Protocols is used in real-time apps.
- 103 Early Hints improves page load speed.
By knowing how 1xx status codes work, you can optimize web interactions better.