MIME Encoded-Word Encode & Decode
Encode non-ASCII email headers (=?UTF-8?B?...?=) and back. This tool does both encode and decode on one page — just pick a mode, paste your text, and click. Everything runs on your device, nothing is sent to a server.
Everything runs in your browser. Your data is never sent to our servers.
Example
Example Input
Café résumé
Example Output
=?UTF-8?B?Q2Fmw6kgcsOpc3Vtw6k=?=
How to Use
- 1Choose Encode or Decode mode at the top.
- 2Type or paste your text into the Input field.
- 3Click the button (or press Ctrl+Enter) to process. The result appears in the Output field.
- 4Click Copy to copy the result, or "Swap input/output" to quickly reverse the operation.
About MIME Encoded-Word
MIME Encoded-Word (RFC 2047) lets non-ASCII characters appear in email headers (like Subject and From), which originally only allow ASCII. The format is: =?charset?encoding?data?=.
How it works: text is encoded with Base64 (B) or Quoted-Printable (Q) then wrapped with charset markers. This tool encodes to the Base64 form (=?UTF-8?B?...?=) and can decode both forms.
Encoded-Word is used by email clients to display subjects/names correctly in any language. It is useful for building or reading international email headers.
FAQ
Can this MIME Encoded-Word tool both encode and decode?
Yes. This is a single page with a toggle — use Encode mode to transform text, and Decode mode to reverse it. No need for two separate pages.
Is my data sent to a server?
No. MIME Encoded-Word is processed entirely in your browser. The text you enter never leaves your device.