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DNS Record Builder & Checker

Create A, AAAA, CNAME, and MX record lines from a spreadsheet and catch conflicting aliases. Work locally without uploading network information.

Runs entirely on your deviceNo uploads, accounts, cookies, or personal tracking.

Validate and build DNS records

Local processing · no input storage

Network tools
Tab-separated absolute owner, type, value, TTL seconds. MX value: preference and absolute mail host. No header; ASCII names with trailing dots.

Generates explicit IN-class record lines, not a complete zone. Checks this supplied batch only. SOA/NS, wildcard names, IDNs, and live DNS are not handled.

Text lists: up to 500 non-empty lines and 256 KiB per field. Tabular results: up to 5,000 rows.

Enter your data, then select validate and build dns records.

Technical reference: RFC 1035 — DNS resource records

1. Add your data

Enter your network data or load the worked example.

2. Choose the result

Validate and build DNS records and review the result and assumptions.

3. Save it locally

Copy the result or download it for your engineering workflow.

About this tool

Use DNS Record Builder & Checker without an upload

Create A, AAAA, CNAME, and MX record lines from a spreadsheet and catch conflicting aliases. Work locally without uploading network information.

The operation runs in the current browser tab. Tool input is not included in aggregate analytics, and the standalone download makes no analytics requests.

Network toolsDeveloper tools