Convert text to Base64 encoding or decode Base64 strings back to readable text, instantly.
Base64 is an encoding scheme, not an encryption method, that converts binary or text data into a set of 64 printable ASCII characters (A-Z, a-z, 0-9, +, /). This Base64 Encoder / Decoder tool lets you convert plain text into its Base64 representation, or take a Base64 string and decode it back into readable text, entirely within your browser using native JavaScript functions.
It's worth being clear about what Base64 is not: it provides no security or confidentiality whatsoever. Anyone can decode a Base64 string back to its original form instantly, with no key or password required — it's purely a format conversion, commonly used to safely represent binary data (like images or files) as text, or to transmit data through systems that only support plain text characters, such as certain email protocols, URLs, or JSON payloads.
Many older systems and protocols were designed to handle plain text only, and could corrupt or misinterpret raw binary data containing arbitrary byte values. Base64 solves this by mapping every 3 bytes of input into 4 printable characters from a fixed alphabet, guaranteeing that the encoded result will pass safely through virtually any text-based system without corruption. This is why you'll commonly see Base64 used in email attachments (MIME encoding), embedded images inside HTML or CSS (data URIs), authentication headers (Basic Auth credentials), and API tokens.
A common pitfall with basic Base64 implementations is mishandling non-ASCII characters, such as emoji or non-English text, because the JavaScript btoa() function technically only supports Latin-1 characters by default. This tool handles that correctly by first converting your text to UTF-8 byte sequences before encoding, and reversing the process precisely on decode, so text containing accented characters, emoji, or any Unicode content round-trips correctly without garbled output.
Developers frequently use Base64 encoding to embed small images directly inside CSS or HTML files without a separate file request, to safely pass binary data through JSON APIs that only accept string values, to encode Basic Authentication credentials in HTTP headers, or to store binary data in text-only fields such as certain database columns or configuration files. It's also commonly used, alongside true encryption, as one processing step when preparing encrypted binary output (like the salt, IV, and ciphertext produced by our Encryption/Decryption tool) for safe copy-pasting as plain text.
Because Base64 is fully reversible without any secret key, never use it as a substitute for real encryption if you need to keep something confidential. If your goal is to protect sensitive text from being read by anyone who intercepts it, use our dedicated Encryption/Decryption tool instead, which applies genuine AES-256-GCM encryption protected by a passphrase you control.
Base64-encoded strings have a recognizable look: a mix of uppercase and lowercase letters and digits, sometimes ending in one or two equals-sign padding characters, with no spaces or punctuation beyond plus signs and slashes. Recognizing this pattern helps you quickly identify when a string you've encountered, perhaps in an API response or a configuration file, is Base64-encoded and can be decoded here to reveal its underlying content.
No. Base64 is purely a format conversion with no secret key involved — anyone can decode it instantly. For real confidentiality, use our Encryption/Decryption tool instead.
This usually happens when the input contains characters outside the standard Base64 alphabet, or when it has been truncated or altered. Make sure you're pasting the complete, unmodified string.
Yes. Text is converted through UTF-8 before Base64 encoding, so accented characters, emoji, and other Unicode text encode and decode correctly.
Email attachments, embedded images in HTML/CSS, API tokens, HTTP Basic Authentication headers, and any system that needs to represent binary data as plain text.
No. All encoding and decoding happens locally using your browser's built-in JavaScript functions.
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