HTTP 303 See Other

HTTP 303 See Other indicates the client must use a different URI to complete the intent. Redirect correctness depends on Location and caching headers, and different clients handle redirects differently—especially for non-GET requests.

Try it (live endpoint)

Response includes the status code, standard headers (including Content-Type), and a small diagnostic JSON body describing the request and returned status.

curl -i "https://httpstatus.com/api/status/303"
Try in playground

Meaning

The response to the request can be found under another URI using a GET method.

What it guarantees
  • A different URI is involved to complete the intent.
What it does NOT guarantee
  • All clients will automatically follow the redirect.
  • The redirect target is safe to cache unless headers allow it.

When to use this status

  • A resource is available at a different URI and the client should follow it.
  • Canonicalizing paths (slash, www/non-www, http→https).
  • Moving content between endpoints and updating bookmarks.

When NOT to use this status (common misuses)

Redirecting without a stable Location target.
Clients fail to follow; crawlers lose canonical signals.
Using 301/302 for non-GET methods without understanding method rewriting.
Clients can drop bodies or change methods, causing data loss and client bugs.
Redirect loops or long chains.
Crawlers waste crawl budget; clients hang; retries amplify load.

Critical headers that matter

Location
Tells clients where to go next.
Redirects fail or loop; crawlers lose canonical target.
Cache-Control
Controls whether redirects are cached.
Temporary redirects become sticky; permanent redirects never stick.
Vary
Prevents caches mixing redirect variants.
CDNs serve the wrong redirect for different hosts/headers.

Tool interpretation

Browsers
Follows Location for navigations; redirect caching can make behavior sticky. Redirect code choice affects method/body handling.
API clients
May not auto-follow; strict clients require explicit redirect handling. Incorrect redirect semantics can drop bodies or change methods.
Crawlers / SEO tools
Uses redirects for canonicalization; long chains/loops waste crawl budget and dilute signals.
Uptime monitors
Typically marks success; advanced checks may flag header anomalies or latency.
CDNs / reverse proxies
Can cache redirects; Location/Vary/Cache-Control correctness drives global consistency.

Inspector preview (read-only)

On this code, Inspector focuses on semantics, headers, and correctness warnings that commonly affect clients and caches.

Signals it will highlight
  • Status semantics vs method and body expectations
  • Header sanity (Content-Type, Cache-Control, Vary) and evidence completeness
  • Redirect chain length, loops, Location presence, protocol safety
Correctness warnings
No common correctness warnings are specific to this code.

Guided Lab outcome

  • Reproduce HTTP 303 See Other using a controlled endpoint and capture the full exchange.
  • Practice distinguishing status semantics from transport issues (redirects, caching, proxies).
  • Validate redirect correctness (Location, hop count, protocol safety) and SEO impact.

FAQ

Should clients retry on HTTP 303?
Usually no—treat it as a successful final response unless your domain requires revalidation.
Is HTTP 303 cacheable?
Only if Cache-Control/validators allow it. Do not assume cacheability from the status alone.
Which headers matter most for HTTP 303?
Content-Type and Cache-Control are the baseline. Some codes also require Location, WWW-Authenticate, or Retry-After.
How does this affect monitoring?
Redirects are policy-dependent; loops and long chains cause false positives and user impact.
How does this affect crawlers/SEO?
Redirect correctness controls canonicalization and crawl budget.
What should error responses include?
If a body is returned, keep it consistent and typed via Content-Type.

Client expectation contract

Client can assume
  • A different URI is involved; Location may be required.
Client must NOT assume
  • Redirects will be followed automatically by all clients.
Retry behavior
Retries are generally unnecessary; treat as final unless domain rules require revalidation.
Monitoring classification
Redirect (policy-dependent)
Validate Location, caching headers, and chain behavior. Redirect loops/chains should alert.

Related status codes

302 Found
The URL of the requested resource has been changed temporarily.
304 Not Modified
Indicates that the resource has not been modified since the version specified by the request headers (If-None-Match or If-Modified-Since). The client should use its cached copy.