# Domain verification diagnoser: find the DNS failure

> Compare a domain with its expected DNS target. Diagnose wrong hosts, proxying, propagation and apex issues, with a link to the provider's fix instructions.

- Canonical HTML page: https://dodomain.io/tools/verify-diagnoser
- This Markdown twin: https://dodomain.io/tools/verify-diagnoser.md
- Site index for agents: https://dodomain.io/llms.txt
- Full documentation as Markdown: https://dodomain.io/docs/llms-full.txt

Generated at build time from the same React source the HTML page renders, never a hand-maintained second copy. Every public page on this host has a twin at `<url>.md`.

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Free tools

## Domain verification diagnoser

Compare your domain with its expected target and get a DNS diagnosis with fix instructions.

### How it works

1. **Paste the expected record.** Enter the full domain, record type and target or verification value supplied by your service.
2. **Compare the DNS evidence.** The engine checks authoritative and public answers, relevant host-entry mistakes, proxy addresses and apex restrictions.
3. **Open the fix instructions.** Read the detected reason and follow the linked provider guide. Retry after editing DNS; incomplete checks are not a failure verdict.

### Use the free API

No API key required. Omit the Accept header for JSON. These read-only checks share a per-address rate limit; a 429 response means wait before trying again.

```
curl --get 'https://app.dodomain.io/api/tools/verify-diagnoser' --data-urlencode 'name=www.example.com' --data-urlencode 'target=customers.example.net' --data-urlencode 'type=CNAME' -H 'Accept: text/markdown'
```

### Verification inside your product

DoDomain's [connect flow](https://dodomain.io/docs/connect-flow) guides customers through setup and verifies their records against authoritative DNS. The [DNS provider guides](https://dodomain.io/docs/guides/dns-providers) explain where to edit each provider's host and target fields.

### Frequently asked questions

#### Which verification failures can this diagnose?

The checks can identify a wrong host, wrong target, missing record, TXT trailing-dot mismatch, a zone appended to a CNAME target, proxy addresses, resolver disagreement and an apex CNAME restriction. If DNS did not answer, the result is indeterminate.

#### Is a trailing dot always wrong?

No. A final dot on a hostname marks an absolute name and is normalized for hostname targets. Some DNS panels append the zone to a target entered as relative; follow the provider's convention. In a TXT verification value a dot is literal text, so an extra dot can make the expected value differ.

#### Why can a working website fail DNS verification?

A Cloudflare proxy can return edge addresses instead of the CNAME target the verifier expects. The tool can identify proxy addresses, but cannot see which origin the proxy forwards to. Follow the provider guide to make the expected DNS record visible.

#### Does propagation mean I should edit the record again?

Not necessarily. When the authoritative record matches but public resolvers disagree, cached answers may still be expiring. Check the resolver views and the provider instructions before making another change.

### Start on the free plan

No card, no sales call: create an app, mint a session, and watch the first domain verify.

[Start with 50 free](https://app.dodomain.io/signin?mode=signup) [Read the quickstart](https://dodomain.io/docs)

### More free tools

- [DNS provider detector](https://dodomain.io/tools/provider-detector)
  
  Which DNS host serves a domain, and whether one-click setup is available there.
- [DNS propagation checker](https://dodomain.io/tools/dns-lookup)
  
  One record, read from the authoritative nameservers and three public resolvers.
- [SPF record checker](https://dodomain.io/tools/spf-checker)
  
  Parse a domain's SPF, walk its includes, count the lookups against the limit of ten.
- [CNAME chain checker](https://dodomain.io/tools/cname-chain)
  
  Follow aliases and flag loops, apex CNAMEs and possible flattening.
- [DNS record diff](https://dodomain.io/tools/dns-diff)
  
  Compare a live DNS snapshot with the expected records you paste in.