Base64 Encode & Decode Online
Encode text to Base64 or decode Base64 to plain text instantly. Supports UTF-8 characters.
About This Tool
The Base64 Encoder/Decoder converts text to Base64-encoded strings and decodes Base64 back to readable text. Base64 encoding is widely used to safely transmit binary data as ASCII text in web applications, email protocols, JWT tokens, and data URLs.
Key Features
- Encode to Base64 — Converts any plain text or Unicode characters into its Base64-encoded representation using the standard RFC 4648 alphabet.
- Decode from Base64 — Converts Base64-encoded strings back into their original readable text, revealing the content of any Base64 payload.
- Swap Direction — One-click Swap button moves the output back to the input and toggles mode for quick round-trip testing.
- Browser-Based Processing — All operations run locally in your browser. Your data never leaves your device.
- Free & No Signup — Use this tool as many times as you need without creating an account or paying anything.
Common Use Cases
- Decoding Base64 strings embedded in JWT tokens to inspect their claims and expiration timestamps
- Encoding images or binary files to Base64 data URIs for embedding directly in HTML or CSS stylesheets
- Decoding Base64 values from API responses, HTTP Authorization headers, or cookie values
- Encoding configuration secrets and API keys for environment variables or base64-encoded config files
- Testing and debugging Base64 encoding in web applications before deployment
How to Use
Select Encode or Decode mode using the buttons at the top. Paste your text into the input area and click the action button. The result appears in the output field below. Use the Swap button to reverse the operation, and Copy to copy the result to your clipboard.
Frequently Asked Questions
What is Base64 encoding?
Base64 represents binary data using 64 printable ASCII characters (A–Z, a–z, 0–9, +, /). It allows binary content to be safely transmitted over channels that only support text, such as email or JSON.
Is Base64 encoding the same as encryption?
No. Base64 is an encoding scheme, not encryption. Anyone can decode Base64 text instantly. It provides no security and should never be used to protect sensitive data.
Why does Base64 increase data size?
Base64 represents 3 bytes of binary data using 4 ASCII characters, increasing size by approximately 33%. This overhead is the trade-off for safe text-based transmission.
Does this tool handle Unicode and emoji?
Yes. The tool encodes text as UTF-8 before Base64 conversion, correctly handling all Unicode characters including accented letters, Chinese characters, and emoji.
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