Amazon Route 53
Managed DNS and domain registration that answers queries, checks endpoint health, and steers users to the right one.
Verified against AWS documentation · 2026-09-09
Key facts
- 01A hosted zone holds one domain's records — public zones answer the internet, private zones answer only the VPCs you attach them to
- 02Eight routing policies: simple, weighted, latency, failover, geolocation, geoproximity, multivalue answer, IP-based
- 03Alias records point at AWS resources, work at the zone apex where CNAME is illegal, and are free to query
- 04Health checks + failover routing give automatic DNS-level failover — but resolvers cache answers, so TTL, not AWS, decides how fast it flips
- 05Exam convention: "the only AWS service with a 100% availability SLA." The current SLA is credit-tiered, with credits starting the moment a hosted zone dips below 100% — flag the gap, answer the convention
Exam triggers
Phrases and scenarios that point here.
- "Lowest latency for global users" → latency routing. "Users in Germany must be served from Frankfurt for legal reasons" → geolocation. Performance vs. law is the whole distinction
- "Send 10% of traffic to the new version" / blue-green / canary → weighted routing
- "Automatically fail over to a standby Region if the primary is down" → health checks + failover routing
- "Point the root domain (example.com) at an ELB, CloudFront, or S3 website" → alias record, never CNAME
- "Resolve internal service names inside the VPC only" → private hosted zone
Not this service
- Caching content close to users to speed up delivery → CloudFront
- Spreading requests across targets inside one Region → Elastic Load Balancing
- Static anycast IPs and failover that ignores DNS caching → Global Accelerator
Use cases
- 01Launching a site end to end — register the domain, alias the apex at a CloudFront distribution, alias www at the same target: no CNAME workarounds and no query charges
- 02Canary releases where rollback is a record edit, not a redeploy — weighted records push 5% at the new stack and drop it back to 0 the moment error rates move
- 03Warm-standby DR across Regions: a health check watches the primary ALB and the failover record promotes the standby before anyone gets paged
- 04Private hosted zones for internal naming, so services call payments.internal.acme instead of a hardcoded IP, and the name resolves nowhere outside the VPC
- 05Geolocation routing driven by contracts rather than performance — a media catalog that must serve a different origin per country because licensing says so
How it's charged
- 01Per hosted zone per month ($0.50 for the first 25) — billed whether the zone answers a billion queries or none, and not prorated; a zone deleted within 12 hours is free
- 02Per million DNS queries answered in public hosted zones, priced by routing type — standard is cheapest, then latency, then geo, then IP-based. Private hosted zone queries are free
- 03Alias queries to AWS targets (ELB, CloudFront, API Gateway, S3 website endpoints, and others) are free; the identical lookup via CNAME is billed, and a CNAME pointing at another Route 53 record bills twice
- 04Health checks are a monthly charge per check, with each optional feature (HTTPS, string matching, fast interval, latency measurement) priced on top — first 50 checks on AWS endpoints are free
- 05Domain registration is a separate annual fee that varies by TLD and has nothing to do with the hosted zone fee — a common surprise when the bill shows both lines
