Base64 Encoder / Decoder

Encode text to Base64 or decode Base64 strings back to plain text. Supports UTF-8 and binary data.

About the Base64 Encoder / Decoder

Base64 encoding converts binary data or text into a radix-64 ASCII string format, commonly used for embedding images directly in HTML/CSS, transmitting data in APIs, or storing binary content in text-only databases. Our tool handles both encoding and decoding with full UTF-8 support, ensuring accurate conversion for international characters and emoji. All processing runs locally in your browser — nothing is sent to any server.

What Is Base64 Encoder / Decoder?

Base64 is a binary-to-text encoding scheme that represents binary data using 64 printable ASCII characters: A–Z, a–z, 0–9, plus '+' and '/' (or '-' and '_' in the URL-safe variant), with '=' used for padding. Every three bytes of input are split into four 6-bit groups, each mapped to one of the 64 characters. The result is a string that can travel safely through systems designed for text — email, JSON, URLs, XML — without corruption from control characters or encoding mismatches. It is important to understand that Base64 is an encoding, not encryption: it provides no confidentiality and can be reversed by anyone. It is typically used when you need to embed or transport binary data inside a text-only medium, not to protect secrets.

How to Use

  1. Enter or paste the text you want to encode/decode in the input field above.
  2. Click 'Encode' to convert your text to Base64 format.
  3. Click 'Decode' to convert a Base64 string back to plain text.
  4. Copy the result using the Copy button.
  5. Use the output in your HTML, CSS, API requests, or data URIs.

Common Use Cases

  • Embedding small images or icons directly in HTML, CSS, or Markdown as data URIs
  • Encoding credentials, tokens, or binary payloads inside JSON or XML API requests
  • Storing binary blobs in text-only storage such as environment variables or .env files
  • Decoding Base64 values found in JWT header/payload sections during debugging
  • Transferring files or binary attachments through email (MIME) and legacy systems

Examples

Input
Hello, 世界 🌍
Output
SGVsbG8sIOS4lueVjCAl8J+Mjg==

UTF-8 text (including emoji) encoded to Base64.

Tips & Best Practices

  • Base64 encoding increases data size by approximately 33%.
  • For image embedding, the Image to Base64 tool on this site offers a dedicated UI.
  • Base64 is commonly used in JSON Web Tokens (JWT) and data URL schemes.
  • UTF-8 support means Chinese characters, emojis, and special symbols encode correctly.

Frequently Asked Questions

Is Base64 the same as encryption?

No. Base64 is a reversible encoding, not encryption. Anyone can decode a Base64 string, so never use it to protect sensitive data. For confidentiality you need a real encryption algorithm such as AES — see the Hash Generator tool for related cryptographic primitives.

Why does my decoded text show garbled characters?

This usually means the original text was encoded in a charset other than UTF-8, or the Base64 string was truncated. Our tool decodes as UTF-8, which covers virtually all modern text including emoji and CJK characters.

What is the URL-safe Base64 variant?

The standard alphabet uses '+' and '/', which have special meaning in URLs. The URL-safe variant replaces them with '-' and '_' and often omits padding. JWTs use the URL-safe variant for all three segments.

How much larger is Base64 than the original?

Roughly 33%. Three input bytes become four Base64 characters, plus possible padding. For binary data like images this overhead is usually acceptable; for large files prefer a direct binary transfer.

This base64 encoder / decoder runs entirely in your browser. No data is uploaded to any server. Your privacy is completely protected.

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