BUY WEBSITES
BUY DOMAINS
LOGIN
SIGNUP
DNS Record Syntax Helper
The DNS Record Syntax Helper is a builder and reference for the records that make a domain resolve: pick a type, fill in the fields, and it assembles a correct zone-file line while validating each value as it is typed. It checks an A record for a real IPv4 address, an AAAA for valid IPv6, MX and SRV for the right priority, weight, port, and host structure, and flags the mistakes that quietly break delegation, such as a CNAME on the zone root or a missing trailing dot.
It is completely free and runs entirely in the browser. The tool never queries DNS or looks a domain up. It only assembles and validates the syntax you describe, so nothing you type is uploaded, which makes it safe for staging zones and records that are not live yet.
🔒 Private: everything runs in your browser. Nothing you paste is uploaded.
Reference and builder only. This tool never queries DNS or looks anything up — it assembles and validates the syntax of the record you describe.
How to use the DNS record syntax helper
Choose a record type tab, complete the host name, TTL, and the type-specific fields, and read the live status pill. Green means the syntax is valid; warnings explain non-fatal issues like a missing trailing dot; red flags a value you must fix before the record will work.
Pick the record type, then fill the fields it actually needs
Each DNS record type carries a different payload, so the helper swaps the field set as the tab changes. An A record needs a single IPv4 address and an AAAA needs IPv6, while CNAME and NS take a host name, MX adds a priority number, and SRV adds priority, weight, and port. The reference panel on the right explains every field for the selected type in plain language. Filling only the relevant fields keeps the record minimal and avoids the guesswork that leads to malformed entries pasted into a provider dashboard.
Watch the validation, because DNS fails silently
A wrong DNS record rarely throws an obvious error; it just quietly fails to resolve or sends traffic to the wrong place. The helper validates IPv4 and IPv6 to their address rules, enforces the 0 to 65535 range on MX and SRV numbers, checks host-name labels against the length and character limits, and refuses an MX or NS that points at a bare IP. It also catches the classic traps, like a CNAME placed on the zone root or a target host missing its trailing dot, so the syntax is correct before it ever reaches your nameserver.
Copy the zone-file line, or map the fields into your provider
The output is a canonical BIND-style line in name, TTL, class, type, data order, the same shape used by most authoritative nameservers and zone exports. Copy it straight into a zone file, or read the assembled fields and type them into a registrar or DNS host that uses a form-based editor rather than raw zone text. TTL controls how long resolvers cache the answer, so lower it before a planned change and raise it again once the record is stable. The line is reference output, not a live lookup or a guarantee of propagation.
DNS record syntax frequently asked questions
Q1What is the difference between an A record and a CNAME?
An A record maps a name directly to an IPv4 address, and an AAAA does the same for IPv6. A CNAME instead aliases one name to another name, which the resolver then follows to find the address. Use an A or AAAA when you control the IP, and a CNAME when you want a subdomain to track another host. A CNAME cannot sit on the zone root or alongside other records on the same name.
Q2Why does my DNS target need a trailing dot?
A trailing dot marks a host name as fully qualified, meaning it is read as an absolute name from the DNS root. Without it, many nameservers treat the value as relative and silently append your own zone, so a target like mail.example.com can become mail.example.com.example.com. The helper warns when a CNAME, MX, NS, or SRV target is missing its trailing dot, because that one missing character is a common and confusing cause of broken resolution.
Q3What do the priority and weight numbers in MX and SRV records mean?
Priority sets the order servers are tried, and the lowest number wins, so a priority 10 mail server is preferred over priority 20. Weight, used only in SRV records, splits traffic between targets that share the same priority, in proportion to their weight values. Both fields accept a whole number from 0 to 65535, and the helper rejects anything outside that range or that is not a plain integer.
Q4Does this DNS tool look up or change my live records?
No. It is a syntax builder and reference only. The tool never queries a nameserver, performs a DNS lookup, or contacts your provider, and it cannot read or modify any record that is already published. Everything runs in your browser, so nothing you type is uploaded or stored. You assemble a correct record here, then publish it yourself through your zone file or DNS host.
Q5What TTL should I set on a DNS record?
TTL is the number of seconds resolvers may cache an answer before asking again. A common default is 3600, one hour, which balances freshness against query load. Lower the TTL to 300 a day or two before a planned change so the switch propagates quickly, then raise it again once the new value is stable. Leaving the field blank uses the zone default. Very short TTLs increase lookups and very long ones slow down updates.
