🧠 Quoted-Printable & Base64 Decoder
Instantly decode MIME-encoded email content — paste and get clean, readable output in your browser. No sign-up, no data stored.
What is a Quoted-Printable & Base64 Decoder?
A Quoted-Printable & Base64 Decoder is an essential online tool for email developers, deliverability engineers, and IT professionals. When emails travel across the internet, their content is often encoded using one of two common MIME encoding standards — Quoted-Printable or Base64. This tool converts that encoded text back into plain, human-readable content instantly, right in your browser.
Both encoding formats are defined by the RFC 2045 and RFC 2047 standards of the MIME (Multipurpose Internet Mail Extensions) specification, which governs how email content is formatted and transmitted globally.
📧 Quoted-Printable
Used for text-heavy content. Encodes special characters as =XX hex values. Keeps most ASCII text readable.
🔐 Base64
Used for binary data or full email bodies. Converts data into a 64-character alphabet string. Fully opaque encoding.
📜 RFC 2045/2047
MIME standards defining email encoding. Our decoder is fully compliant with both specifications.
How to Use the Decoder
- Select the Decoding Method: Choose either Quoted-Printable or Base64 from the dropdown menu.
- Paste Your Encoded Content: Open your email source (in Gmail: three-dot menu → "Show original"), copy the encoded body, and paste it into the input field.
- View Instant Output: Decoded output appears live as you type — no button press needed.
- Copy the Result: Click the Copy button to copy decoded text to your clipboard.
Where to find encoded email content
In Gmail, open an email → click the three-dot menu (⋮) → select "Show original". Look for lines like
Content-Transfer-Encoding: quoted-printable or Content-Transfer-Encoding: base64 to
identify the encoding method used.
Why Use Our Free Decoder?
- 🚀 Instant Results — Decoding happens live in your browser as you type.
- 🔒 100% Private — Your data never leaves your browser; nothing is logged or stored.
- 🆓 Completely Free — No subscriptions, no accounts, no limits.
- ✅ RFC Compliant — Fully supports RFC 2045 and RFC 2047 standards.
- 📱 Works on Any Device — Mobile-friendly, fully responsive design.
Common Use Cases
This tool is widely used by email deliverability engineers to debug encoding issues, by developers to decode API responses or JWT payloads, and by sysadmins to inspect raw email headers and body content for postmaster troubleshooting.