DNS & domain lookup

DNS Zone File Validator

Validate a BIND-format DNS zone file: parse records and catch syntax errors, unknown types and missing SOA/NS. Free, runs entirely in your browser.

Validate a DNS zone file

Paste a BIND-format zone file to parse its records and check for errors.

What this zone file validator does

Parses BIND-format zone files into records
Handles $TTL, owner inheritance and ttl/class ordering
Flags unknown types and malformed record data
Checks for required SOA and NS records
Ignores comments and blank lines correctly
Runs entirely in your browser

Common use cases

  1. 1Checking a zone file before importing it
  2. 2Catching syntax errors after hand-editing
  3. 3Reviewing an exported zone from another provider
  4. 4Verifying required SOA and NS records exist
  5. 5Learning zone file structure
  6. 6Auditing a migration between DNS hosts

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About DNS zone files

A zone file is the master text file that defines all DNS records for a domain, in BIND format. Each line has an owner name, TTL, class, type and data, with a required SOA record and one or more NS records. Many providers let you import and export zones in this format.

This validator parses the file the way a nameserver roughly would and flags obvious problems — unknown types, malformed addresses, missing SOA/NS — so you catch mistakes before they cause resolution failures. It runs locally in your browser.

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HostCloud.in  ·  Pune, India  ·  Serving 34,987+ Websites Since 2020

FREQUENTLY ASKED QUESTIONS

Got Questions? We Have Answers.

What is a DNS zone file?

A zone file is the master text file, in BIND format, that defines all DNS records for a domain — with a required SOA record and one or more NS records.

What does the validator check?

It parses each record, handles $TTL and owner inheritance, flags unknown types and malformed data (like invalid IPs), and warns if the SOA or NS records are missing.

Is my zone file uploaded?

No. Parsing happens entirely in your browser — the file never leaves your device.

Why does my record show a warning?

Common causes are an unknown record type, an A record that is not a valid IPv4 address, an unquoted TXT value, or a malformed MX line. The message names the line and issue.

Is this a full BIND parser?

It handles the common cases well, but it is a pragmatic validator rather than a complete RFC1035 implementation. Use it to catch obvious mistakes before importing.

Can I load an example?

Yes. Use the "Load sample" button to see a valid zone file you can edit and re-validate.