{"id":64597,"date":"2025-05-12T10:38:48","date_gmt":"2025-05-12T07:38:48","guid":{"rendered":"https:\/\/wpcalc.com\/en\/?p=64597"},"modified":"2026-09-28T09:57:04","modified_gmt":"2026-09-28T06:57:04","slug":"base64-decoder","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/en\/web-tools\/base64-decoder\/","title":{"rendered":"Base64 Decoder"},"content":{"rendered":"<section class=\"not-prose calculator-box\" aria-labelledby=\"calculator-title\"><div class=\"flex items-baseline sm:items-center justify-between gap-2 sm:gap-3\"><div class=\"flex flex-col sm:flex-row sm:items-center gap-2\"><span class=\"icon icon-calculator text-primary-700! text-base! dark:text-primary-300!\" aria-hidden=\"true\"><\/span><h2 id=\"calculator-title\" class=\"text-lg font-display font-bold\">Base64 to Text Decoder Tool<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"64597\" data-favorite-title=\"Base64 Decoder\" data-favorite-url=\"https:\/\/wpcalc.com\/en\/web-tools\/base64-decoder\/\" data-favorite-excerpt=\"Decode a Base64 string and view the resulting text. Paste encoded content into the Base64 String field to see the decoded output.\" aria-label=\"Add to Favorites\" data-favorite-icon=\"icon icon-conversion\">\n    <span class=\"icon icon-shape-star-empty\" aria-hidden=\"true\"><\/span>\n  <\/button>\n  <div class=\"calcdash-favorite__tip\" aria-hidden=\"true\">\n   <span class=\"favorite-tooltip\" id=\"favorite-tooltip\"><\/span>\n  <\/div>\n  <span class=\"sr-only\" role=\"status\" id=\"favorite-status\"><\/span>\n<\/div><\/div><form action=\"https:\/\/wpcalc.com\/en\/web-tools\/base64-decoder\/\" method=\"POST\" class=\"calculator\" id=\"calculator-64597\" data-post=\"64597\"><fieldset class=\"fieldset-input is-1\"><legend class=\"sr-only\">Input Fields<\/legend><div class=\"field is-single\" id=\"input-1\"><label for=\"field-1\">Base64 String<\/label><textarea id=\"field-1\" name=\"base64_string\">SGVsbG8gd29ybGQh<\/textarea><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Re-Calculate\" id=\"calculate-button\" data-post=\"64597\">Calculate<\/button><button type=\"reset\">Reset<\/button><\/div><div class=\"field is-checkbox hidden!\" id=\"field-auto-calc\"><input type=\"checkbox\" id=\"auto-calc\"><label for=\"auto-calc\">Calculate automatically<\/label><small>If enabled, the result will update automatically when you change any value.<\/small><\/div><div class=\"fieldset-result is-hidden\" aria-labelledby=\"result-title\" aria-live=\"polite\" role=\"region\"> <h3 class=\"result-title bg-gradient-to-r from-primary-50 to-gray-50 dark:from-primary-900 dark:to-gray-800\" id=\"result-title\"><span class=\"icon icon-s-pulse\" aria-hidden=\"true\"><\/span> Your Results<\/h3><div class=\"result-box\"><div class=\"field-result is-column\" id=\"output-1\"><span class=\"field-title\"><span>Decoded Text<\/span><\/span><span class=\"field-value\" id=\"result-1\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copy Result\" aria-label=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><\/div><div class=\"result-actions\"><button type=\"button\" class=\"copy-link\"><svg viewBox=\"0 0 20 20\" fill=\"currentColor\" aria-hidden=\"true\"><path d=\"M12.232 4.232a2.5 2.5 0 0 1 3.536 3.536l-1.225 1.224a.75.75 0 0 0 1.061 1.06l1.224-1.224a4 4 0 0 0-5.656-5.656l-3 3a4 4 0 0 0 .225 5.865.75.75 0 0 0 .977-1.138 2.5 2.5 0 0 1-.142-3.667l3-3Z\"\/><path d=\"M11.603 7.963a.75.75 0 0 0-.977 1.138 2.5 2.5 0 0 1 .142 3.667l-3 3a2.5 2.5 0 0 1-3.536-3.536l1.225-1.224a.75.75 0 0 0-1.061-1.06l-1.224 1.224a4 4 0 1 0 5.656 5.656l3-3a4 4 0 0 0-.225-5.865Z\"\/><\/svg><span class=\"copy-link__text\">Copy link to this calculation<\/span><\/button><span class=\"sr-only\" role=\"status\" id=\"copy-link-status\"><\/span><\/div><\/div><a href=\"#respond\" class=\"hidden transition-opacity duration-300 opacity-0 w-50 text-sm justify-center items-center gap-2 px-4 py-2 rounded bg-gray-200 text-gray-700 hover:bg-gray-300\" id=\"leave-comment\"><span class=\"icon icon-comments\" aria-hidden=\"true\"><\/span>Leave a Comment<\/a><\/form><\/section><section id=\"calc-reactions\" class=\"not-prose hidden my-12 bg-gradient-to-r from-primary-50 to-gray-50 border border-indigo-100 rounded-xl px-6 py-4 shadow-sm\" data-post=\"64597\" aria-live=\"polite\" aria-labelledby=\"calc-reactions-title\"><p id=\"calc-reactions-title\" class=\"text-sm text-gray-500 text-center mb-2\">How did this result make you feel?<\/p><div role=\"group\" aria-labelledby=\"calc-reactions-title\" class=\"grid grid-cols-3 sm:flex sm:flex-row sm:justify-around gap-4 sm:items-center sm:flex-wrap\"><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"like\"><span class=\"reaction-count\" data-reaction-count=\"like\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude00 <\/span><span class=\"reaction-description font-medium\">Like <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"helpful\"><span class=\"reaction-count\" data-reaction-count=\"helpful\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\udca1 <\/span><span class=\"reaction-description font-medium\">Helpful <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"confused\"><span class=\"reaction-count\" data-reaction-count=\"confused\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude15 <\/span><span class=\"reaction-description font-medium\">Confused <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"disappointed\"><span class=\"reaction-count\" data-reaction-count=\"disappointed\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude1e <\/span><span class=\"reaction-description font-medium\">Disappointed <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"inaccurate\"><span class=\"reaction-count\" data-reaction-count=\"inaccurate\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\u274c <\/span><span class=\"reaction-description font-medium\">Inaccurate <\/span><\/button><\/div><div id=\"reaction-message\" class=\"hidden mt-8 rounded-md border border-primary-100 bg-white\/50 backdrop-blur-sm px-4 py-2 text-sm text-center shadow-sm\"><\/div><\/section><div class=\"calcdash-ad not-prose calcdash-ad--calc_result calcdash-ad--in-article\"><ins class=\"adsbygoogle\" style=\"display:block\" data-ad-client=\"ca-pub-1721569815777345\" data-ad-slot=\"6317458308\" data-ad-layout=\"in-article\" data-ad-format=\"fluid\"><\/ins><script>(adsbygoogle = window.adsbygoogle || []).push({});<\/script><\/div>\n<style id=\"wpcoderpro-inline-1\">.formula-box {\r\n\tborder-bottom: none !important;\r\n}<\/style><section class=\"formula-box\" aria-labelledby=\"formula-title\">\r\n\t<div id=\"formula-title\" class=\"not-prose font-display mb-4\"><span class=\"icon icon-formula\" aria-hidden=\"true\"><\/span><h2>Base64 Decoder Formula<\/h2><\/div>\r\n\t<figure class=\"not-prose formula\">\r\n\t\t<figcaption class=\"formula-title\">Formula<\/figcaption>\r\n\t\t<div class=\"text-base text-gray-800\" id=\"formula\">\n\\[ b_1=4v_1+\\left\\lfloor\\frac{v_2}{16}\\right\\rfloor,\\quad b_2=16(v_2\\bmod16)+\\left\\lfloor\\frac{v_3}{4}\\right\\rfloor,\\quad b_3=64(v_3\\bmod4)+v_4 \\]\n<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>Where:<\/strong><\/p>\n<ul>\n<li>\\(v_1,v_2,v_3,v_4\\) \u2014 the values, from 0 to 63, represented by four Base64 characters.<\/li>\n<li>\\(b_1,b_2,b_3\\) \u2014 the three decoded bytes, each from 0 to 255.<\/li>\n<\/ul>\n<p>Each complete group of four Base64 characters represents three bytes. The equations recover those bytes by reversing the way Base64 divides them into six-bit values; a final group with padding produces fewer bytes.<\/p>\n<p>\r\n<\/section>\n<style id=\"wpcoderpro-inline-459\">.calculation-box {\r\n\tborder-bottom: none !important;\r\n}<\/style><section id=\"calculation\" class=\"calculation-box\" aria-labelledby=\"calculation-title\">\r\n\t<div id=\"calculation-title\" class=\"not-prose font-display\"><span class=\"icon icon-unordered-list\" aria-hidden=\"true\"><\/span><h2>Base64 Decoder \u2013 Calculation Example<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Example:<\/strong> the default Base64 String, <code>SGVsbG8gd29ybGQh<\/code>, contains the encoded message \u201cHello world!\u201d.<\/p>\n<p>\\[ \\operatorname{atob}(\\texttt{SGVsbG8gd29ybGQh})=\\text{Hello world!} \\]<\/p>\n<p><strong>Result:<\/strong> the Decoded Text is <code>Hello world!<\/code>.<\/p>\n<p>\n\r\n<\/section>\n<h2>How to use the Base64 Decoder<\/h2>\n<ol>\n<li>Paste or type your encoded content into the <strong>Base64 String<\/strong> field. You can leave the default value in place to try the example above.<\/li>\n<li>Read the <strong>Decoded Text<\/strong> result. For the default input, it displays <code>Hello world!<\/code>.<\/li>\n<li>Use the result\u2019s copy control if you need to paste the decoded text elsewhere. If the result says \u201cInvalid Base64 string,\u201d check the input for characters that do not belong in standard Base64.<\/li>\n<\/ol>\n<p>The calculator trims whitespace from the beginning and end of your input before decoding. You can paste a complete string without adding quotation marks or a label such as <code>base64:<\/code>; those extra characters would become part of the input.<\/p>\n<h2>What Base64 decoding means<\/h2>\n<p>Base64 is a way to represent bytes using a limited set of text characters: letters, digits, <code>+<\/code>, and <code>\/<\/code>, with <code>=<\/code> sometimes used as padding at the end. It is often used when data needs to pass through a text-based format, such as an API response or an email message. Decoding reverses that representation; it does not decrypt the data or change what the original bytes mean.<\/p>\n<p>This calculator uses the browser\u2019s <code>atob()<\/code> function. Its output is a string in which each character represents one decoded byte. Ordinary ASCII text, including the default example, therefore appears as expected. If the original data was a file, compressed data, or another non-text format, the result may contain unreadable characters rather than useful prose.<\/p>\n<p>For text outside ASCII, the distinction between bytes and characters matters. UTF-8 uses multiple bytes for many accented letters, symbols, and emoji, but this tool does not perform a separate UTF-8 conversion after Base64 decoding. A valid Base64 string containing UTF-8 text can consequently produce garbled-looking output. That appearance does not necessarily mean the Base64 itself is invalid.<\/p>\n<h2>Input limits and practical tips<\/h2>\n<p>This tool expects Base64 that the browser\u2019s <code>atob()<\/code> function accepts. Standard Base64 commonly ends in one or two <code>=<\/code> padding characters, although the browser may also accept a valid final group without padding. Missing padding alone is not a reliable sign of an error. If decoding fails, check for copied punctuation, an incomplete string, or characters from a different encoding format.<\/p>\n<p>URL-safe Base64 commonly substitutes <code>-<\/code> for <code>+<\/code> and <code>_<\/code> for <code>\/<\/code>. This calculator does not convert those characters automatically. If your source explicitly uses URL-safe Base64, make those substitutions before entering it. Likewise, if the encoded value is embedded in a URL, first extract the Base64 portion; use the <a href=\"https:\/\/wpcalc.com\/en\/web-tools\/url-decoder\/\">URL Decoder<\/a> when the URL itself contains percent-encoded characters.<\/p>\n<p>If you need to turn text into Base64 rather than decode it, use the <a href=\"https:\/\/wpcalc.com\/en\/web-tools\/base64-encoder\/\">Base64 Encoder<\/a>. To inspect byte values in a different notation, the <a href=\"https:\/\/wpcalc.com\/en\/web-tools\/hex-converter\/\">Hex Converter<\/a> and <a href=\"https:\/\/wpcalc.com\/en\/web-tools\/binary-converter\/\">Binary Converter<\/a> cover those representations. None of these conversions makes sensitive content private: Base64 is an encoding, not a security measure.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Decode a Base64 string and view the resulting text. Paste encoded content into the Base64 String field to see the decoded output.<\/p>\n","protected":false},"author":70,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[63],"tags":[64],"class_list":["post-64597","post","type-post","status-publish","format-standard","hentry","category-web-tools","tag-converter-tools"],"acf":[],"_links":{"self":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/64597","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/users\/70"}],"replies":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/comments?post=64597"}],"version-history":[{"count":3,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/64597\/revisions"}],"predecessor-version":[{"id":65326,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/64597\/revisions\/65326"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/media?parent=64597"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/categories?post=64597"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/tags?post=64597"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}