Quoted-Printable Encoder + Decoder

Quoted-printable is the encoding used in email message bodies for content that's "mostly ASCII but with some 8-bit characters." It preserves printable ASCII and escapes non-printable / high-bit bytes as =XX hex. This converter handles both directions with proper soft-line-break support (the = at end of line).

How to use the Quoted-Printable Encoder + Decoder

Pick encode or decode. The output updates live. Soft line breaks (lines ending with =) are added automatically when encoding to keep lines under 76 characters per RFC 2045.

About Quoted-Printable Encoder + Decoder

Quoted-printable (RFC 2045 §6.7) is one of two transfer encodings standard in MIME email (the other is base64). Designed for text bodies that are mostly ASCII with occasional high-bit characters — it produces output that's still mostly readable, unlike base64 which is opaque.

Rules:

• Printable ASCII characters (32-126 except =) are kept as-is.
• Any other byte is encoded as =XX (uppercase hex).
• Tab (9) and space (32) are kept as-is in most positions but must be encoded if they appear at end of line (would be stripped by mail transports).
• The = character itself encodes as =3D.
• Lines longer than 76 characters get a soft line break: = at end of line, which the decoder removes.
• Hard line breaks in the source remain as CRLF.

You'll see quoted-printable in email message Content-Transfer-Encoding: quoted-printable bodies — modern systems often prefer base64 or 8bit but qp is still widely used for plain-text bodies.

Common use cases

• Reading raw email source — decode the body to see the actual content.
• Email debugging — when a sender's name is mangled, qp decoding usually fixes it.
• MIME header decoding — combined with =?UTF-8?Q?...?= encoded-word syntax for Subject lines.
• Generating MIME messages — encode body content for outgoing email.