Base64 Encoder & Decoder
Encode and decode text in Base64 format.
About This Tool
Base64 Encoder/Decoder is a free browser-based tool that converts plain text to Base64 encoding and decodes Base64 strings back to readable text. It correctly handles the full UTF-8 character set — including international characters, accented letters, and emoji — using the browser's native TextEncoder and TextDecoder APIs.
Base64 is a widely used encoding standard (RFC 4648) that represents binary data as printable ASCII characters. It is used in HTML and CSS data URIs for inline images, in MIME email attachments, in HTTP Basic authentication headers, in JSON Web Tokens (JWT), and in many API protocols that transmit binary data over text-based channels.
This tool is most useful for web developers embedding images as data URIs, backend engineers debugging API tokens and headers, and anyone needing to quickly inspect or generate Base64-encoded data without writing a script.
How to Use
- 1
Paste your text into the input field.
- 2
Click Encode to convert text to Base64, or Decode to convert Base64 back to text.
- 3
Copy the result with the copy button.
- 4
Paste Base64 data from emails, data URIs, or API responses to decode it back to readable text.
- 5
Use the Encode output in HTML data URIs, HTTP headers, or configuration files that require Base64.
Features
Encode & Decode
Switch instantly between encoding plain text to Base64 and decoding Base64 back to text.
UTF-8 Support
Handles international characters and emoji correctly using the TextEncoder/TextDecoder API.
Instant Results
Encoding and decoding happens instantly in your browser with no server calls.
Error Detection
Invalid Base64 strings are detected and a clear error message is shown.
Common use cases
- ›Encode images as Base64 data URIs for use in HTML, CSS, or email templates.
- ›Decode JWT tokens or API keys passed as Base64 in HTTP headers or query strings.
- ›Inspect Base64-encoded email attachments or MIME payloads.
- ›Convert credentials for HTTP Basic Authentication headers in API testing.
Read our guide
Base64 Encoder & Decoder — Complete Guide →FAQ
What is Base64?
Base64 is an encoding scheme that converts binary data into ASCII text, commonly used for data transfer.
Does it support Unicode?
Yes, it handles UTF-8 text correctly using TextEncoder/TextDecoder.
What is Base64 used for?
Base64 is used to embed binary data in text formats: images in CSS/HTML data URIs, attachments in email (MIME), tokens in HTTP headers, and credentials in Basic authentication.
Is Base64 encryption?
No. Base64 is an encoding scheme, not encryption. Encoded data can be decoded by anyone without a key. Do not use it to protect sensitive data.
Why does Base64 output end with = or ==?
Base64 encodes 3 bytes into 4 characters. If the input is not a multiple of 3 bytes, one or two '=' padding characters are added to make the output a complete group.