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GZIP Compression for API Responses

GZIP compression is a widely used method to reduce the size of data transmitted between the backend and frontend, improving the speed and efficiency of web applications.

How GZIP Compression Works

  1. Middleware Integration: GZIP middleware is added to the backend server (FastAPI) to automatically compress API responses.
  2. Response Size Threshold: The backend is configured to compress responses only if the payload size exceeds a certain threshold (e.g., 500 KB). This ensures that only large responses are compressed, optimizing resource usage.
  3. Client Request Headers: The frontend must indicate support for GZIP by setting the request header: 
    {
    "Accept-Encoding": "gzip"
}
  4. Compressed Response: If the response size is greater than 500 KB, the backend compresses the data and sends it to the frontend.
  5. Decompression on Frontend: The frontend automatically decompresses the GZIP response and displays the original data to the user.

Example Flow

  1. User requests data from the frontend.
  2. Frontend sends request with Accept-Encoding: gzip header.

  3. Backend checks response size:

    • If ≤ 500 KB: Sends uncompressed data.
    • If > 500 KB: Compresses data using GZIP and sends compressed response.

  4. Frontend receives and decompresses the response, then renders the original data.

Benefits

  • Reduced Bandwidth Usage: Compressing large responses significantly reduces the amount of data transferred over the network.
  • Faster Load Times: Smaller payloads result in faster API response times and improved user experience.
  • Seamless Integration: Most modern browsers and HTTP clients natively support GZIP decompression.