Base64 Encoder & Decoder
Encode and decode Base64 strings instantly in your browser
About Base64
Base64 encodes binary data as ASCII text. Uses native btoa() / atob() — no data leaves your browser.
How to Use This Tool
- Choose the mode: "Encode" to convert text to Base64, or "Decode" to convert Base64 back to plain text.
- Paste or type your input into the text field.
- The result is generated instantly as you type.
- Click "Copy" to copy the encoded or decoded output to your clipboard.
Common Use Cases
- Encoding binary data (images, files) to embed directly in HTML, CSS, or JSON.
- Decoding Base64-encoded API response payloads to inspect their content during debugging.
- Encoding credentials for HTTP Basic Authentication headers (username:password → Base64).
- Embedding small images as Base64 Data URIs in CSS to eliminate extra HTTP requests.
- Decoding the payload section of a JWT token for quick inspection without a dedicated tool.
Frequently Asked Questions
What is Base64 encoding?
Base64 is an encoding scheme that converts binary data into a safe ASCII string representation using 64 printable characters (A–Z, a–z, 0–9, +, /). It is commonly used to transmit binary data through systems that only handle text.
Does Base64 encrypt my data?
No. Base64 is encoding, not encryption. It is trivially reversible by anyone — there is no secret key involved. Never use Base64 to hide or protect sensitive information.
Why does Base64 output have "=" padding at the end?
Base64 encodes every 3 bytes of input as 4 characters. When the input length is not a multiple of 3, one or two "=" characters are added as padding to keep the output length a multiple of 4.
How does this tool handle non-ASCII (Unicode) characters?
The tool converts the input to UTF-8 bytes before encoding, ensuring that Unicode characters such as emoji and accented letters are correctly handled. Decoding reverses this process.