Upload Resumption Supported
Experimental code indicating the server supports resumable uploads.
What it means
The HTTP 104 Upload Resumption Supported is an experimental informational status code. It is used to inform the client that the server supports resumable uploads for the current request.
This is particularly useful when uploading massive files over an unstable network. If the connection drops, the client doesn't need to restart the upload from the beginning.
How it works
- 1The client begins an upload request.
- 2The server immediately responds with a '104 Upload Resumption Supported' interim response.
- 3If the upload fails mid-way, the client can use the provided mechanisms (like the Draft Resumable Uploads standard) to resume the upload from the exact byte where it disconnected.
Why you're seeing this
- • The server is advertising support for advanced resumable uploads.
How to fix it
- • If you are a client library maintainer, intercept this 1xx response and enable your resumable upload logic for the current connection.
Framework Implementations
Node.js
// Note: This is highly experimental and not supported out of the box in most frameworks yet.
res.write('HTTP/1.1 104 Upload Resumption Supported\r\nLocation: /upload/session_id\r\n\r\n');Real-Life Scenarios
Use this only when implementing experimental resumable upload protocols on APIs handling massive file uploads (e.g., 10GB+ video files).
Mobile Video Uploads
A user is uploading a 20-minute 4K video from their phone while on a train. The network drops. Because the server sent 104, the app knows it can resume exactly where it left off once the connection returns.
HTTP Transaction
1. Client Request
POST /upload HTTP/1.1 Host: storage.example.com Upload-Length: 1000000 Content-Length: 50000
2. Server Response
HTTP/1.1 104 Upload Resumption Supported Location: https://storage.example.com/upload/xyz123 (Client then sends data...)
SEO Implications
None. Informational status codes do not affect SEO, and search engines do not upload massive files.