Encoding Decoder
Turn the gibberish in an email back into words. And back again.
Base64, quoted-printable, RFC 2047 encoded subject lines, URL encoding. Paste it and the format is detected for you. Useful whenever a header or a MIME part refuses to read as English.
Which is which
Base64 turns any data into letters, digits, + and /, usually padded with =. Attachments and many HTML bodies travel this way — it's why an attachment looks like meaningless characters in a raw email.
Quoted-printable keeps normal text readable and escapes only the awkward characters as = plus two hex digits. A line ending in a bare = is a soft line break, not part of the text. If you're seeing =E2=80=99 where an apostrophe should be, this is what you have.
RFC 2047 encoded words are how non-English subject lines survive. They look like =?UTF-8?B?…?= or =?UTF-8?Q?…?= — the letter in the middle tells you whether the inside is Base64 or quoted-printable. Decoding handles both, and leaves any surrounding plain text alone.
URL encoding uses %20 style escapes. Common in tracking links and unsubscribe URLs.
About the character set
Base64 and quoted-printable produce bytes, not letters — something has to decide which alphabet those bytes represent. UTF-8 is right almost always. If the result comes out full of é or ’, try Windows-1252 or Latin-1, which is usually an older mail client at the other end.
Encoded words carry their own charset in the =?…?= wrapper, so that dropdown is ignored for those.
Nothing is uploaded
All of it happens in this tab. That matters here more than most places — the thing you're decoding is often part of a real email.
What the encoding decoder does
The Encoding Decoder turns the scrambled-looking text you sometimes find in emails back into normal words. It handles Base64, quoted-printable, encoded subject lines like =?UTF-8?B?...?=, and URL encoding, and it can work out which one you have on its own. It also works the other way, so you can encode plain text when you need to.
Benefits
- Detects the format for youPaste the text and the tool tells you whether it found Base64, quoted-printable, an encoded subject line or URL encoding. You can also pick the format yourself.
- Fixes odd subject linesEncoded words in subjects and headers are decoded in place, and any normal text around them is left as it is.
- Handles both decode and encodeSwitch to Encode to turn plain text into Base64, quoted-printable, an encoded word or URL encoding.
- Choose the right character setIf the result shows strange symbols, pick a different character set such as Windows-1252, Latin-1, ISO-8859-15, Shift JIS or GB18030 and try again.
- Reads tracking and unsubscribe linksPercent-encoded links become readable, so you can see where a link really points.
- Flip results back and forthOne button moves the output into the input and switches direction, so you can check that text decodes and encodes cleanly.
- Copy or save the resultCopy the output to your clipboard or download it as a text file.
Who it is for
- Small business owners puzzled by an email subject that shows up as a string of symbols.
- IT helpers reading the raw source of an email to troubleshoot a problem.
- Developers testing how their app encodes email headers and bodies.
- Marketers checking where a tracking or unsubscribe link actually leads.
- Anyone who opened a raw email file and found long blocks of unreadable text.
How to use it
- Choose Decode or Encode.
- Paste your text into the Input box.
- Leave the format on Detect automatically, or pick one, and change the character set if needed.
- Click Convert, then copy or download the output.
Your privacy
All decoding and encoding happens in your browser tab. Nothing you paste is sent to ListaFix or anyone else.
Common questions
Why does my email subject look like =?UTF-8?B?...?=
That's an RFC 2047 encoded word, which is how non-English subject lines survive transmission. The letter in the middle tells you whether the inside is Base64 (B) or quoted-printable (Q). Paste the whole thing here and it decodes, leaving any surrounding plain text alone.
What does =E2=80=99 mean in an email?
It's quoted-printable encoding — an escape for a character that couldn't travel as-is. That particular one is a curly apostrophe. A line ending in a bare = is a soft line break, not part of the text.
What is Base64?
An encoding that turns any data into letters, digits, plus and slash, usually padded with equals signs. Attachments and many HTML email bodies travel this way, which is why an attachment looks like meaningless characters in a raw email.
Why does my decoded text come out full of strange characters?
The character set is wrong. Base64 and quoted-printable produce bytes, and something has to decide which alphabet those bytes represent. UTF-8 is right almost always; if you're seeing sequences like é or ’, try Windows-1252 or Latin-1.
Is anything uploaded?
No. All encoding and decoding happens in this browser tab, which matters because the thing being decoded is usually part of a real email.