Quoted-Printable Encoder / Decoder
About this Tool
AllThatConverter's Quoted-Printable encoder and decoder is a free online tool that converts text to and from the Quoted-Printable (QP) format defined in RFC 2045. It is useful for debugging email delivery issues, decoding MIME-encoded message headers, and testing SMTP systems. All processing runs locally in your browser with no uploads. No registration required, completely free.
Processed safely on your device
Everything happens in your browser on this device. Your files are never sent to our servers—so you can use it with peace of mind.
How to Use
Paste the text or QP-encoded string you want to convert into the input area.
Click 'QP Encode' or 'QP Decode'.
The result appears instantly in the output area.
Click 'Copy' to copy the result and paste it into your email or system.
Key Scenarios & Use Cases
Email Delivery Debugging
Decode QP-encoded text found in received email source to diagnose character encoding or garbling issues.
MIME Email Header Parsing
Decode MIME-encoded subject lines and sender names (=?UTF-8?Q?...?=) to read the original text.
Mail System Development and Testing
Verify QP encoding output when developing SMTP servers or mail-sending APIs to ensure correct delivery.
Legacy System Compatibility Checking
Inspect and verify QP-encoded data for compatibility with 7-bit-limited or legacy mail transport systems.
Frequently Asked Questions (FAQ)
Quoted-Printable is designed for mostly-ASCII text with occasional non-ASCII characters; it is more human-readable and produces smaller output than Base64 for such content. Base64 is used for arbitrary binary data.
Yes. Non-ASCII characters are converted to UTF-8 bytes and encoded as =XX hexadecimal escape sequences.
Yes. =?UTF-8?Q?...?= MIME-encoded subject lines can be decoded to their original text.
No. All processing runs locally in your browser. Nothing is transmitted externally.