DNS TXT Record Splitter
Split a long TXT value such as a DKIM key into 255-byte quoted strings for a zone file, or join quoted strings from dig output back into one value.
Free · No sign-up · Your inputs stay in your browser
Input
Split or join long DNS TXT records
Output
For a zone file
410 characters in 2 strings
One string inside a TXT record holds at most 255 bytes (RFC 1035), so a 2048-bit DKIM key has to be several strings in one record; resolvers hand them back concatenated with nothing in between. That is different from several TXT records, which are separate values. Many DNS panels split for you and some do not, which is why dig output for a DKIM record shows two quoted halves.
Runs in this browser. Nothing you paste is sent to a server.
About this tool
Method, assumptions, practical next steps, and limits.
One record, several strings
A character-string in DNS holds at most 255 bytes (RFC 1035), but a TXT record can hold several, and resolvers return them together for the application to concatenate without separators. That is different from several TXT records at the same name, which are separate values: splitting a DKIM key into two records breaks it.
Provider differences
Route 53, Cloudflare and most panels split long values automatically when you paste them; some older panels and BIND zone files need it done by hand.