Free online MBOX to TXT converter

An email archive may need conversion when a script, editor, records system, or device accepts plain UTF-8 files instead of mailbox databases. TXT is also easier to search, quote, and share, but it cannot retain email folders, formatting, or attachments as separate objects.

What the MBOX format is

MBOX is a mailbox container that stores multiple email messages sequentially in one file, with each message separated by a line beginning with From . It is used by Mozilla Thunderbird, Apple Mail, Unix mail systems, and several older or open-source email clients. You commonly encounter it after exporting a mailbox, migrating between mail programs, recovering an old profile, or downloading an archive from a mail service.

An MBOX file contains email headers, message bodies, and often MIME parts for HTML content and attachments. It is not a document format, so changing its extension to .txt does not convert the messages into readable plain text.

What the TXT format is

TXT is a plain-text format containing characters without email-client metadata, HTML styling, mailbox indexes, or layout instructions. It works with text editors, command-line tools, OCR and indexing systems, scripts, and devices that accept UTF-8 text.

TXT is useful when you need a searchable transcript or a compact, portable representation of message content. It is smaller than an archive containing decoded attachments and does not require an email application, but it cannot preserve clickable links, rich formatting, labels, threading, or attachments in their original form.

How to actually convert MBOX to TXT

Use the online converter

1. Open the free converter on 101convert.com.
2. Select the MBOX file and choose TXT as the output format.
3. Start the conversion and save the generated .txt file.

Use this method for a quick readable export when the archive does not require custom filtering. Do not use it for confidential mail unless the service's handling and retention terms meet your requirements.

Convert locally with Python

The Python standard library can extract the first plain-text body from every message and write one UTF-8 document. Save the following as mbox_to_txt.py:

import mailbox
import sys


def get_body(message):
    if message.is_multipart():
        for part in message.walk():
            if part.get_content_type() == 'text/plain' and not part.get_filename():
                return decode_part(part)
        return '[No plain-text body; the message may contain HTML only]'
    return decode_part(message)


def decode_part(part):
    raw = part.get_payload(decode=True)
    if raw is None:
        value = part.get_payload()
        return value if isinstance(value, str) else ''
    charset = part.get_content_charset() or 'utf-8'
    return raw.decode(charset, errors='replace')

source, destination = sys.argv[1], sys.argv[2]
with mailbox.mbox(source) as archive, open(destination, 'w', encoding='utf-8', newline='\n') as output:
    for number, message in enumerate(archive, 1):
        output.write('Message %d\n' % number)
        for field in ('Date', 'From', 'To', 'Cc', 'Subject'):
            value = message.get(field)
            if value:
                output.write('%s: %s\n' % (field, value))
        output.write('\n')
        output.write(get_body(message).rstrip())
        output.write('\n\n' + ('=' * 72) + '\n\n')

Run it from a terminal with:

python mbox_to_txt.py archive.mbox mail.txt

On Windows, use py mbox_to_txt.py archive.mbox mail.txt if the python command is unavailable. Replace the filenames with the actual paths; quote paths containing spaces.

Quality and compatibility limitations

• The script prefers text/plain. Messages containing only HTML produce a placeholder instead of a rendered body; converting HTML to readable plain text requires a separate HTML parser or an email client export.
• Attachments are not embedded in the output. Their filenames and MIME headers may be omitted, while binary data is unsuitable for a readable TXT file.
• Characters that use an unknown or invalid source encoding are replaced during UTF-8 decoding. Review multilingual messages after conversion.
• The output combines all messages into one file and inserts separators. It does not preserve mailbox folders, labels, read status, threading, dates as sortable metadata, or the original raw MIME source.
• Keep the original MBOX as the archival copy. TXT is a content extract, not a reversible replacement for the mailbox.