2xx SuccessHTTP Status Code Reference

HTTP 226 IM Used— What It Means, Causes & How to Fix It

The server has fulfilled a GET request for the resource, and the response is a representation of the result of one or more instance-manipulations applied to the current instance. Used with delta encoding.

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Common Causes

  • Delta encoding applied to reduce bandwidth
  • Instance manipulation via If-Modified-Since with IM header
  • Server applying feed differences for efficient sync

How to Fix

  1. 1No fix needed — delta encoding is working correctly
  2. 2Ensure client can reconstruct the full resource from the delta
  3. 3Verify the IM header specifies a supported manipulation

Example

HTTP 226 IM Used
GET /feed HTTP/1.1
A-IM: feed
If-None-Match: "abc"

→ 226 IM Used
→ Only the changes since version "abc"

Related Success Codes

200

OK

201

Created

202

Accepted

203

Non-Authoritative Information

204

No Content

205

Reset Content

206

Partial Content

207

Multi-Status

208

Already Reported

Commonly Referenced Status Codes

The most frequently searched HTTP status codes

200OK201Created204No Content301Moved Permanently302Found400Bad Request401Unauthorized403Forbidden404Not Found422Unprocessable Content429Too Many Requests500Internal Server Error502Bad Gateway503Service Unavailable504Gateway Timeout

Related Tools

HTTP Status LookupAPI Request BuildercURL GeneratorHTTP Header ViewerHTTP Header DiffRedirect Checker