Base64 Encoder / Decoder
Encode or decode Base64 strings easily. Use this tool to convert between readable text and Base64 for safe data transfer or storage.
Input Settings
No input entered
Encoded Result
Encoded result will appear here
Enter text and click "Convert" to start
About Base64 Encoder / Decoder
Base64 encoding is a binary-to-text encoding scheme that represents binary data in ASCII format by translating it into a radix-64 representation. This tool allows you to easily encode text or binary data into Base64 format or decode Base64 strings back to their original readable form, making it essential for data transmission and storage in text-based protocols.
Why use a Base64 Encoder / Decoder?
Base64 encoding ensures that data remains intact without modification during transport through systems that are designed to deal with textual data. It's widely used in email attachments, embedding images in HTML/CSS, API authentication tokens, and storing binary data in JSON or XML where only text is allowed.
Who is it for?
Web developers, software engineers, system administrators, and anyone working with APIs, email systems, or data serialization will find this tool invaluable. It's particularly useful for developers working with authentication systems, data URIs, or integrating with services that require Base64-encoded data.
How to use the tool
Paste or type your text/data into the input field
Select 'Encode' to convert your text to Base64 format, or 'Decode' to convert Base64 back to readable text
Click the encode/decode button to process your data
Copy the result from the output field
Use the encoded/decoded data in your application or system
Frequently Asked Questions
How do I encode/decode Base64 online?
Paste text into the input area and click Encode for Base64-encoded output; paste Base64 and click Decode for the original text. The tool supports both UTF-8 text and binary content (via file upload). Choose between standard Base64 (uses +/) and URL-safe Base64 (uses -_). Output includes proper '=' padding. Encoding/decoding runs entirely in your browser — your text never leaves the device. Verifiable in DevTools' Network tab: zero HTTP requests during conversion.
What is Base64?
Base64 is a binary-to-text encoding that represents arbitrary binary data as ASCII text using 64 characters (A-Z, a-z, 0-9, +, /). Defined in RFC 4648. Used for embedding binary data (images, files, certificates) in text-only contexts: email (MIME attachments), JSON, XML, data URIs, JWT, X.509 certificates (PEM format), HTTP basic auth headers. Each Base64 character represents 6 bits of input, so 3 input bytes produce 4 output characters. The result is always safe to include in any text protocol.
Is Base64 encryption or secure?
**NO — Base64 is NOT encryption.** It's a trivially-reversible encoding designed for safe text representation of binary data, not security. Anyone can decode Base64 with a few lines of code in any language. If you Base64-encode a password, anyone seeing the encoded string can decode it instantly. For security, use proper encryption (AES, RSA, etc.). Base64 is appropriate for: embedding binary in text; sending non-ASCII data through ASCII-only channels; data URIs in HTML/CSS. Not for: passwords, secrets, sensitive data.
Is my data sent to a server when I encode?
No — encoding/decoding runs entirely in your browser using JavaScript's built-in `btoa()` / `atob()` functions (or modern equivalents for UTF-8). Your input never reaches a server, never gets logged. Verify in DevTools' Network tab: encoding produces zero HTTP requests. Safe for sensitive data (though see the 'is Base64 secure' FAQ — encoding doesn't add security; storing Base64-encoded secrets in source code is still leaking them).
Why does Base64 inflate file size?
Base64 represents 3 binary bytes as 4 ASCII characters (each character holds 6 bits). The size increase is ~33% (4/3 = 1.333). A 100 KB binary file becomes ~133 KB when Base64-encoded. Plus padding: '=' characters fill the output to multiples of 4. The trade-off is text-safety: Base64 can safely travel through email, JSON, URLs (with URL-safe variant), HTTP headers — anywhere binary would cause encoding issues. For embedding tiny files (<1 KB icons), Base64 is acceptable; for larger files, use external file references.
What's the difference between standard Base64 and URL-safe Base64?
Standard Base64 (RFC 4648 §4) uses A-Z, a-z, 0-9, + and /. The + and / cause problems in URLs (where they have special meaning) and in filenames (in some OSes). URL-safe Base64 (RFC 4648 §5) replaces + with - and / with _, making the output safe in URLs without escaping. Both use = for padding (sometimes URL-safe omits = for shorter output). JWT uses URL-safe without padding. Choose based on the destination context: standard for general use, URL-safe for URLs/filenames/JWT.
What is the '=' at the end of a Base64 string?
Padding. Base64 output length must be a multiple of 4 characters (since it encodes 6 bits × 4 = 24 bits = 3 bytes of input). When the input length isn't a multiple of 3 bytes, the encoder pads with '=' characters: 0, 1, or 2 '=' characters at the end. Decoders use the padding to know exactly how many input bytes the encoded data represents. Some 'URL-safe' Base64 variants omit padding (you must know the length elsewhere). For most uses, padding is fine; for very compact storage, omit it.
When should I use Base64?
Common cases. (1) Embedding binary in text-only formats (JSON, XML, YAML, source code). (2) Email attachments (MIME). (3) Data URIs for small images in HTML/CSS (`data:image/png;base64,...`). (4) JWT (header, payload, and signature use URL-safe Base64). (5) Encoding HTTP Basic auth credentials (`Authorization: Basic <base64-encoded user:pass>`). (6) PEM certificates and keys. NOT for: encryption, password storage, anywhere you need security or compactness — use proper encryption for security, gzip+binary for compactness.
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