200 vs 204: OK vs No Content
200 and 204 can look similar in logs, but they tell clients, crawlers, and API consumers different things.
| Aspect | HTTP 200 — OK | HTTP 204 — No Content |
|---|---|---|
| Definition | The server successfully processed the request and is returning the requested resource or result. This is the most common status code in normal web traffic. | Commonly used for DELETE operations, form submissions, or PUT updates where no body is needed in the response. The client should not navigate away or reload. |
| Plain-language summary | The server received the request, processed it, and is returning the result. This is the expected response for most GET, POST, PUT, and PATCH requests. If you see 200 in your logs, the connection and request lifecycle completed without error — though the business logic in the response body may still contain application-level errors depending on the API design. | HTTP 204 No Content indicates the request succeeded but there is no content to return. |
| When to use | Return 200 when the request succeeded and there is a body to return. For successful creation use 201. For successful deletion or updates with no body use 204. Avoid wrapping error messages inside 200 responses — it breaks client error handling and monitoring dashboards. | HTTP 204 No Content indicates the request succeeded but there is no content to return. |
| Client behavior | Clients display the response body as-is. Browsers render the page. API clients parse the JSON body. No retry is attempted. If caching headers are present, the response may be stored. | Client handles 204 according to success semantics. |
| Caching behavior | Cacheable by default if Cache-Control, Expires, or Last-Modified headers are present. Without explicit cache headers, client behavior varies. Set Cache-Control: no-store for dynamic API responses, or appropriate max-age for stable resources. | See 204 caching spec. |
| SEO / crawler impact | Search crawlers interpret 200 (success) for indexation and link equity accordingly. | Search crawlers interpret 204 (success) for indexation and link equity accordingly. |
| API / backend impact | API clients branching on 200 expect OK semantics. | API clients branching on 204 expect No Content semantics. |
| Safe to retry? | Only after fixing the underlying cause | Only after fixing the underlying cause |
Common real-world scenarios
When you see HTTP 200
High-volume 200s are normal. Watch for latency spikes on 200 responses — they indicate slow processing before the successful response. Alert on p99 latency, not just 5xx rate. Application errors returned inside 200 bodies (common in older RPC-style APIs) are invisible to standard APM dashboards unless you parse the body.
When you see HTTP 204
204 appears in production when: Normal protocol behavior.
Decision rule
Use 200 when the response should communicate ok behavior; use 204 when no content is the accurate protocol signal.
A frequent mistake is swapping 200 and 204 for convenience; that causes client retry bugs, incorrect cache signals, and misleading monitoring data.
Use 200 when the correct protocol signal is OK. Use 204 when the correct signal is No Content. Returning either code for the wrong reason breaks client expectations, cache behavior, and monitoring accuracy.
FAQ
What is the biggest difference between 200 and 204?
200 communicates OK, while 204 communicates No Content. Choosing the right one keeps clients and intermediaries predictable.
Do 200 and 204 have SEO or caching impact?
Yes. Search engines and caches interpret status classes differently. Use each code according to its semantics to avoid accidental indexing, stale responses, or crawl inefficiency.
Can APIs safely return 200 instead of 204?
Only when it matches contract semantics. API clients often branch logic by exact code, so swapping them can break retries, auth handling, or user-facing errors.
Full guides
HTTP 200 OK — full guide · HTTP 204 No Content — full guide · All comparisons · HTTP 200 status reference · HTTP 204 status reference