Base64 Encoder and Decoder Online Tool

Convert text to Base64 format and back with our free online tool. Supports multiple character encodings and output formats.

Input

Output

How to Use This Base64 Encoder/Decoder Tool

Encoding Text to Base64

  1. Enter your text in the input box
    • Type directly or paste from clipboard
    • Use the paste button for convenience
  2. Select character encoding from dropdown
    UTF-8(Recommended for all languages)
    ASCII(English only)
    ISO-8859-1(Western Europe)
    40+ others(Specialized needs)
  3. Click "Encode to Base64" button
  4. Copy your result from output box
    • Use the copy button
    • Or standard Ctrl+C/Cmd+C

Decoding Base64 to Text

  1. Paste your Base64 string in the input box
  2. Select original encoding used during encoding
    Critical: Using wrong encoding will corrupt the output
  3. Click "Decode from Base64" button
  4. View decoded text in output box

Understanding Character Encodings

Encoding
Supported Languages/Characters
When to Use
UTF-8
All modern languages (English, Chinese, Arabic, etc.)
Default choice for international text
ASCII
Basic English (letters, numbers, common symbols)
Legacy systems, English-only content
ISO-8859-1 (Latin-1)
Western European (French, Spanish, German, etc.)
Older European systems
Windows-1252
Extended Western European
Windows legacy applications
Other Encodings
40+ specialized encodings available
Specific regional/language requirements

Key Technical Details

Base64 Fundamentals

  • Character Set: A-Z, a-z, 0-9, +, /, =
  • Padding: Uses = characters to make length divisible by 4
  • Size Increase: ~33% larger than original binary
  • Binary Support: Can encode any binary data as text

Common Issues & Solutions

  • Gibberish output? Try different encodings
  • URL usage? Manually replace +/ with -_
  • Padding errors? Ensure correct = count
  • Large data? Process in smaller chunks

Security Notice

  • Base64 is not encryption - encoded data is easily reversible
  • Never use for passwords or sensitive information
  • For secure data, use proper encryption before encoding

Frequently Asked Questions

Standard Base64 uses '+' and '/' characters which can cause issues in URLs. URL-safe Base64 replaces these with '-' and '_' respectively. Our tool automatically handles both formats when decoding.

The character encoding determines how text is converted to binary before Base64 encoding. Using different encodings for encoding and decoding will produce incorrect results. UTF-8 is recommended for most cases as it supports all Unicode characters.

Our tool automatically removes line breaks when processing Base64 strings. If you need to preserve line breaks (for MIME formatting), you'll need to add them back manually after encoding.

Currently, the tool processes one text string or file at a time. For batch processing, you would need to use each item separately or consider a desktop solution with batch capabilities.

The equals signs are padding characters that make the Base64 string length a multiple of 4. They're part of the standard Base64 specification. Our tool automatically handles padding during both encoding and decoding.

While there's no strict limit, very large texts may cause browser performance issues. For texts larger than a few megabytes, consider breaking them into smaller chunks or using a desktop solution.