An origin server is the system where your content or application actually lives and where responses are created. A CDN, cache or reverse proxy sits in front of it, answering many requests itself and contacting the origin only when it needs fresh content.
Why it matters
If the origin is slow or down, a CDN can mask the problem for cached pages but fail on anything uncached, producing errors like Cloudflare's 52x family. Keeping the origin's real IP private matters too, because attackers who find it can bypass the CDN's protections. And origin capacity must still handle cache misses, purges and traffic spikes.
Example
Checking the origin directly while bypassing public DNS, using a resolve override:
curl -sI --resolve example.com:443:203.0.113.20 https://example.com/If this returns 200 while the public URL fails, the problem is in the CDN, DNS or edge layer rather than the origin. Compare headers such as Server and Age between the two to see which layer answered.
Common mistakes
- Leaving the origin reachable by anyone, instead of allowing only CDN IP ranges.
- Exposing the origin IP in old DNS records or email headers.
- Assuming a green CDN status means the origin is healthy.
Related
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This page is general information written by our editorial team and updated when documentation changes. Servers and providers differ, so test changes safely first. See our editorial policy and disclaimer.