Base64 Encoder/Decoder
Encode text to Base64 or decode Base64 strings back to plain text instantly.
About Base64 Encoder/Decoder
Encode and decode Base64 strings online for free. Convert text to Base64 encoding or decode Base64 back to readable text. Useful for data URIs, API tokens, email encoding, and more. Runs entirely in your browser.
What Is Base64 Encoding?
Base64 is a binary-to-text encoding scheme that converts binary data into a set of 64 printable ASCII characters. It uses the letters A-Z, a-z, digits 0-9, and two additional characters (+ and /), with = used for padding. Base64 is not encryption — it does not provide security. It is a reversible encoding method designed to safely transmit binary data through systems that only handle text, such as email protocols and JSON APIs.
How to Use This Tool
To encode, paste plain text into the input field and click Encode. The tool converts your text to its Base64 representation instantly. To decode, paste a Base64 string into the input field and click Decode to reveal the original plain text. The tool handles standard Base64 encoding (RFC 4648) and will alert you if the input is not valid Base64 when decoding.
Why Base64 Is Used
Base64 encoding solves a fundamental problem in computing: how to transmit binary data through channels designed for text. Email attachments use Base64 because the SMTP protocol was designed for 7-bit ASCII text. Data URIs in HTML and CSS embed images directly in code using Base64. API authentication headers often encode credentials in Base64. JWT tokens encode their header and payload sections as Base64URL. Anywhere binary data needs to travel through a text-only channel, Base64 is the standard solution.
How Base64 Encoding Works
Base64 works by taking every 3 bytes (24 bits) of input and splitting them into 4 groups of 6 bits each. Each 6-bit group maps to one of 64 characters in the Base64 alphabet. If the input length is not divisible by 3, padding characters (=) are added to the output. This means Base64-encoded data is always about 33% larger than the original. For example, the text "Hello" (5 bytes) becomes "SGVsbG8=" (8 characters) in Base64.
Base64 vs Encryption
A common misconception is that Base64 provides security. It does not. Base64 is a fully reversible encoding — anyone can decode a Base64 string back to its original content without any key or secret. Never use Base64 to hide sensitive data like passwords, API keys, or personal information. For actual data protection, use proper encryption algorithms like AES. Base64 is for data transport compatibility, not confidentiality.
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