Group of binary-to-text encoding schemes using 64 symbols (plus padding)

<span class="mw-page-title-main">Base64</span>

Base64

<p>In <a href="/en/Computer_programming" title="Computer programming" class="wl">computer programming</a>, <b>Base64</b> is a group of <a href="/en/Binary-to-text_encoding" title="Binary-to-text encoding" class="wl">binary-to-text encoding</a> schemes that represent <a href="/en/Binary_data" title="Binary data" class="wl">binary data</a> (more specifically, a sequence of 8-bit <a href="/en/Byte" title="Byte" class="wl">bytes</a>) in sequences of 24 <a href="/en/Bit" title="Bit" class="wl">bits</a> that can be represented by four 6-bit Base64 digits.</p>

<div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none" about="#mwt1">Group of binary-to-text encoding schemes using 64 symbols (plus padding)</div>
<p>Common to all binary-to-text encoding schemes, Base64 is designed to carry data stored in binary formats across channels that only reliably support text content. Base64 is particularly prevalent on the <a href="/en/World_Wide_Web" title="World Wide Web" class="wl">World Wide Web</a><span class="mw-ref reference" id="cite_ref-1"><a href="#cite_note-1" style="counter-reset: mw-Ref 1;"><span class="mw-reflink-text">[1]</span></a></span> where one of its uses is the ability to embed <a href="/en/Image_files" title="Image files" class="mw-redirect wl">image files</a> or other binary assets inside textual assets such as <a href="/en/HTML" title="HTML" class="wl">HTML</a> and <a href="/en/CSS" title="CSS" class="wl">CSS</a> files.<span class="mw-ref reference" id="cite_ref-2"><a href="#cite_note-2" style="counter-reset: mw-Ref 2;"><span class="mw-reflink-text">[2]</span></a></span></p>

<p>Base64 is also widely used for sending <a href="/en/E-mail" title="E-mail" class="mw-redirect wl">e-mail</a> attachments. This is required because <a href="/en/Simple_Mail_Transfer_Protocol" title="Simple Mail Transfer Protocol" class="wl">SMTP</a><span>&nbsp;</span>– in its original form<span>&nbsp;</span>– was designed to transport <a href="/en/7-bit_ASCII" title="7-bit ASCII" class="mw-redirect wl">7-bit ASCII</a> characters only. This encoding causes an overhead of 33–37% (33% by the encoding itself; up to 4% more by the inserted line breaks).</p>

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In computer programming, Base64 is a group of binary-to-text encoding schemes that represent binary data in sequences of 24 bits that can be represented by four 6-bit Base64 digits. Common to all binary-to-text encoding schemes, Base64 is designed to carry data stored in binary formats across channels that only reliably support text content. Base64 is particularly prevalent on the World Wide Web Base64 is also widely used for sending e-mail attachments. This is required because SMTP – in its original form – was designed to transport 7-bit ASCII characters only. This encoding causes an overhead of 33–37% . 