Quoted-printable converter
Encode a MIME body as quoted-printable or decode one to exact bytes and readable text.
- 1Add input
- 2Adjust settings
- 3Get your result
Tool input and files are processed in this browser without being uploaded.
Before you start
Encode UTF-8 body text with MIME line breaks, or encode any file from its exact bytes. Decode a quoted-printable body to the original bytes and preview text using UTF-8 or Windows-1252.
How to use this tool
- Choose Encode or Decode, then choose pasted body text or a file.
- For decoding, paste only the quoted-printable body or select a .txt/.qp file; choose its charset from the MIME Content-Type header for the text preview.
- Convert, check the line-break and byte facts, then copy complete text or download the exact decoded bytes.
Supported inputs and limits
Paste up to 1 MiB of text. Choose one file up to 2 MiB for encoding or 7 MiB for decoding; a decode file must contain ASCII quoted-printable body text.
This handles one MIME body part, not a whole .eml message, multipart boundaries or RFC 2047 encoded headers. Invalid escapes are rejected; overlong source lines and transport padding are reported.
Text encoding normalizes meaningful line breaks to CRLF. File encoding preserves original bytes. Decoded bytes are always downloadable; charset selection affects only the readable preview.
Worked example
Example input
Café = yes
Example options
{"mode":"encode"}Example output
Caf=C3=A9 =3D yes
When something does not work
Remove MIME headers and boundaries, then check =XX escapes and dangling equals signs. If text is unreadable, check the Content-Type charset or download decoded.bin.
Frequently asked questions
Can I paste an entire email or Subject header?
No. Extract one MIME body part first. This tool does not parse multipart boundaries or RFC 2047 encoded words in email headers.
Why do long lines end in an equals sign?
Quoted-printable uses = followed by a line break to wrap a long encoded line without adding a real break to the decoded bytes. Encoded lines are at most 76 characters.
What if the decoded bytes are not readable UTF-8?
Choose Windows-1252 only if the MIME Content-Type says that charset, or download decoded.bin for exact bytes. decoded.txt is available only when the chosen charset produces readable text.
What happens to line breaks and trailing spaces?
Pasted body text is encoded with CRLF hard line breaks. File encoding preserves original bytes. During decoding, soft breaks disappear, hard break bytes are preserved, and raw trailing transport padding is ignored.
Is my input sent to a server?
No. Conversion happens in your browser. Save the result before closing the tab.
Documentation & further reading
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