Code Examples
Here are examples of how to test HTTP 304 responses in different programming languages:
Select options below to see how to use advanced features in your code:
curl https://free.mockerapi.com/304
{
"success": true,
"status": 304,
"statusText": "Not Modified - Used for caching purposes - the response has not been modified",
"timestamp": "2025-10-08T10:30:45.123Z",
"request": {
"method": "GET",
"url": "/304",
"fullUrl": "https://free.mockerapi.com/304"
}
}fetch('https://free.mockerapi.com/304')
.then(response => {
console.log('Status:', response.status); // 304
return response.json();
})
.then(data => {
console.log('Success:', data);
})
.catch(error => {
console.error('Error:', error);
});{
"success": true,
"status": 304,
"statusText": "Not Modified - Used for caching purposes - the response has not been modified",
"timestamp": "2025-10-08T10:30:45.123Z",
"request": {
"method": "GET",
"url": "/304",
"fullUrl": "https://free.mockerapi.com/304"
}
}import requests
response = requests.get('https://free.mockerapi.com/304')
print(f'Status Code: {response.status_code}') # 304
print(f'Response: {response.json()}'){
"success": true,
"status": 304,
"statusText": "Not Modified - Used for caching purposes - the response has not been modified",
"timestamp": "2025-10-08T10:30:45.123Z",
"request": {
"method": "GET",
"url": "/304",
"fullUrl": "https://free.mockerapi.com/304"
}
}{
"success": true,
"status": 304,
"statusText": "Not Modified - Used for caching purposes - the response has not been modified",
"timestamp": "2025-10-08T10:30:45.123Z",
"request": {
"method": "GET",
"url": "/304",
"fullUrl": "https://free.mockerapi.com/304"
}
}require 'net/http'
require 'json'
uri = URI('https://free.mockerapi.com/304')
response = Net::HTTP.get_response(uri)
puts "Status Code: #{response.code}" # 304
puts "Response: #{JSON.parse(response.body)}"{
"success": true,
"status": 304,
"statusText": "Not Modified - Used for caching purposes - the response has not been modified",
"timestamp": "2025-10-08T10:30:45.123Z",
"request": {
"method": "GET",
"url": "/304",
"fullUrl": "https://free.mockerapi.com/304"
}
}package main
import (
"fmt"
"io"
"net/http"
)
func main() {
resp, err := http.Get("https://free.mockerapi.com/304")
if err != nil {
panic(err)
}
defer resp.Body.Close()
fmt.Printf("Status Code: %d\n", resp.StatusCode) // 304
body, err := io.ReadAll(resp.Body)
if err != nil {
panic(err)
}
fmt.Printf("Response: %s\n", body)
}{
"success": true,
"status": 304,
"statusText": "Not Modified - Used for caching purposes - the response has not been modified",
"timestamp": "2025-10-08T10:30:45.123Z",
"request": {
"method": "GET",
"url": "/304",
"fullUrl": "https://free.mockerapi.com/304"
}
}import java.net.http.*;
import java.net.URI;
public class HttpStatusTest {
public static void main(String[] args) throws Exception {
HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create("https://free.mockerapi.com/304"))
.GET()
.build();
HttpResponse response = client.send(request,
HttpResponse.BodyHandlers.ofString());
System.out.println("Status Code: " + response.statusCode()); // 304
System.out.println("Response: " + response.body());
}
} {
"success": true,
"status": 304,
"statusText": "Not Modified - Used for caching purposes - the response has not been modified",
"timestamp": "2025-10-08T10:30:45.123Z",
"request": {
"method": "GET",
"url": "/304",
"fullUrl": "https://free.mockerapi.com/304"
}
}const https = require('https');
https.get('https://free.mockerapi.com/304', (res) => {
console.log('Status Code:', res.statusCode); // 304
let data = '';
res.on('data', (chunk) => {
data += chunk;
});
res.on('end', () => {
console.log('Response:', JSON.parse(data));
});
}).on('error', (err) => {
console.error('Error:', err.message);
});{
"success": true,
"status": 304,
"statusText": "Not Modified - Used for caching purposes - the response has not been modified",
"timestamp": "2025-10-08T10:30:45.123Z",
"request": {
"method": "GET",
"url": "/304",
"fullUrl": "https://free.mockerapi.com/304"
}
}What is HTTP 304 Not Modified?
HTTP 304 Not Modified indicates that the request has more than one possible response. The server is informing the client that there are multiple options available for the requested resource, and the user or user agent should choose one of them.
This status code is rarely used in practice. When implemented, the server should include a list of resource characteristics and locations from which the user or user agent can choose the most appropriate one.
When Does This Happen?
A 304 Not Modified response is returned when:
- A resource is available in multiple formats (e.g., different languages, file formats)
- Multiple versions of a resource exist and the server wants the client to choose
- The server cannot determine which representation to return based on the request headers
- Content negotiation requires explicit user selection
Try It Live
Click the button below to make a live request and see the 304 Not Modified response
Common Use Cases
🌐 Content Negotiation Testing
Test how your application handles multiple resource options and content negotiation scenarios.
🔄 Multi-Format Resources
Mock responses for resources available in multiple formats (JSON, XML, etc.) or languages.
📋 Version Selection
Test client behavior when multiple versions of an API or resource are available.
🎯 Client Choice Testing
Verify that your application properly handles scenarios where user selection is required.
🔍 API Documentation
Demonstrate multiple choice scenarios in API documentation with working examples.
🧪 Edge Case Testing
Test rarely-used HTTP status codes to ensure comprehensive error handling.