HTTP 102 Processing

What It Means

The HTTP 102 Processing status code is an interim response used to inform the client that the server has received the complete request and is working on it. This prevents the client from timing out while waiting for a response to a long-running request.

Origin

This status code is defined in RFC 2518 as part of the WebDAV (Web Distributed Authoring and Versioning) specification. It's specifically designed for operations that may take a significant amount of time to complete.

When It's Used

Large file operations: Copying or moving large files on a WebDAV server
Complex queries: Operations that require significant server-side processing
Batch operations: Processing multiple resources in a single request

Example Scenario

# Client initiates large COPY operation
COPY /documents/large-folder HTTP/1.1
Host: webdav.example.com
Destination: /backup/large-folder

# Server sends interim response
HTTP/1.1 102 Processing

# ... server continues processing ...

# Server sends final response
HTTP/1.1 201 Created
Location: /backup/large-folder

Key Points

This is an interim response, not a final one
A final status code (2xx, 4xx, 5xx) will follow
Primarily used in WebDAV contexts, rarely seen in standard HTTP
Helps prevent client-side timeouts during long operations
Deprecated in HTTP/2 and HTTP/3 (use different mechanisms)

Modern Alternatives

For modern APIs, consider these patterns instead:

202 Accepted + polling: Return immediately, client polls for status
Webhooks: Notify client when processing completes
WebSockets: Push progress updates to the client

Frequently Asked Questions

What is HTTP 102 Processing?

HTTP 102 Processing is an interim informational response defined in the WebDAV specification (RFC 2518). It tells the client that the server has received the complete request and is still working on it. This prevents the client from timing out while waiting for a long-running operation to complete.

Is 102 Processing still used in modern APIs?

102 Processing is rarely used in modern REST APIs. It has been deprecated in newer HTTP specifications. Modern APIs typically use 202 Accepted with a polling pattern, webhooks, or WebSocket connections to handle long-running operations instead of sending interim 102 responses.

What is the difference between 102 Processing and 202 Accepted?

102 Processing is an interim response, meaning the server will send a final response later on the same connection. 202 Accepted is a final response that tells the client the work has been queued and they should check back later via a separate request (polling). 202 is the modern, preferred approach.

Can 102 Processing be used with HTTP/2 or HTTP/3?

102 Processing is not supported in HTTP/2 or HTTP/3. These newer protocols have different mechanisms for handling long-running requests. If you need to support long operations, use the 202 Accepted pattern with polling, server-sent events, or WebSockets instead.

When might I encounter a 102 response?

You might encounter 102 Processing when working with WebDAV servers during large file copy, move, or batch operations. Microsoft SharePoint and some enterprise document management systems may use it. Outside of WebDAV contexts, this status code is essentially never seen.