📨 Email Subject Encoder & Decoder

Encode and decode email subjects using RFC 2047 — Quoted-Printable, Full Hex QP, and Base64. Works instantly in your browser with full UTF-8 support.

⬆️ Encoder — Type to encode instantly

Enter Email Subject / From field to Encode:

Encodes to RFC 2047 Quoted-Printable, Full Hexadecimal Quoted-Printable & Base64.

📝 Quoted Printable Encoding — Space Representation

RFC 2047 allows space as _ (underscore) or =20 (hex). Choose your preferred form.

QP Encoded Output:

Full Hex Quoted Printable:

Base64 (RFC 2047):

🔢 Hexadecimal Encoding -RFC 2047 QP encoded-word.

Positions (e.g. 1,3,5):

Hex Encoded Output:

🌫️ Blurry Encoding

Positions (e.g. 2,4,6):

Blurry Encoded Output:

🔀 Multiple Encoded -Words RFC 2047 encoded-word blocks

Split every N chars:

Multiple Encoded Words Output:

⬇️ Decoder — Paste encoded text to decode

Quoted-Printable Decoder Input:

Decoded QP Output:

Base64 Decoder Input:

Decoded Base64 Output:

What is an Email Subject Encoder / Decoder?

An Email Subject Encoder & Decoder is a tool that converts special characters, Unicode text, and non-ASCII characters in email subject lines into formats that are safely transmitted by email servers worldwide. Without proper encoding, subject lines containing symbols like ©, ®, or characters in Hindi, Arabic, Chinese, or other non-Latin scripts will appear as garbled text or ? characters to recipients.

This problem is solved by RFC 2047, an IETF standard that defines the "encoded-word" mechanism for email headers. Our tool implements all three formats defined by RFC 2047 — Quoted-Printable, Hex Quoted-Printable, and Base64 — making it the most complete free subject encoder available online.

📧 Quoted-Printable (QP)

Encodes only special characters, keeping ASCII text readable. Best for subjects with mostly Latin text.

🔢 Full Hex QP

Encodes every character as a hex value. More compatible with older or strict mail servers.

🔐 Base64

Encodes the entire string in Base64. Best for non-Latin scripts (Chinese, Arabic, Hindi, etc.).

How to Use the Subject Encoder

Type your subject: Enter your email subject or "From" display name in the text field above. All three encoded formats are generated instantly.
Choose the format: Select either Quoted-Printable, Full Hex QP, or Base64 depending on your ESP or mail server's requirements.
Copy & paste: Click the Copy button next to the desired output and paste it into your email's subject header.
Decode existing subjects: Paste a raw encoded subject line into the decoder sections to see the original, human-readable text.

Which format should I choose?

For subjects with mostly English text and a few special characters (like ™, ©, accented letters), use Quoted-Printable — it keeps most characters human-readable. For subjects in non-Latin scripts (Hindi, Arabic, Chinese, Japanese), use Base64 for the best compatibility across all email clients.

Why Use Our Free Email Subject Encoder?

⚡ Live Encoding — All three output formats update in real-time as you type.
🌍 Full UTF-8 Support — Handles all scripts including Hindi, Arabic, Chinese, Korean, and more.
✅ RFC 2047 Compliant — Outputs are tested and compliant with IETF email header standards.
🔒 100% Private — Processing happens in your browser; no data is sent to any server.
🆓 Always Free — No limits, no sign-up, no subscription.
📱 Works on Any Device — Responsive design for desktop, tablet, and mobile.

Who uses this tool?

This tool is commonly used by email marketing professionals building campaigns in ESPs like Mailchimp, SendGrid, and PMTA, developers configuring SMTP servers and transactional email headers, and deliverability engineers who need to inspect and reconstruct encoded email headers from raw message sources.