Base64 Encoder

Convert UTF-8 text or local file bytes to Base64. Choose standard (+/ with padding) or URL-safe (-_ without padding) output, and optionally wrap standard output at 76 characters.

  • Runs entirely in your browser
  • No data stored or sent to a server
  • Free forever — no signup
  • Instant conversion

Input and Output

Use the interactive encoder and decoder on this page to process your text.

Learn more about Base64 encoding

How to Encode Text to Base64 (With Examples)

Base64 Encoding

When to Use Base64 Encoding

Use Base64 encoding when you need to represent binary or text data in an ASCII-safe format — for JSON payloads, data URIs, email attachments, JWT segments, or API fields that only accept text.

Real-World Examples

Plain text: Hello → SGVsbG8=

Credentials header: user:pass → dXNlcjpwYXNz

Unicode: café → UTF-8 bytes encoded as Base64

Common Mistakes

  • Treating Base64 as encryption — it is encoding only and fully reversible
  • Double-encoding output that was already Base64
  • Assuming all Base64 uses the same alphabet (URL-safe variants use -_ instead of +/)
  • Including line breaks in payloads that expect a single continuous string

Edge Cases

  • Empty input returns a validation message — enter text before encoding
  • Padding (=) appears when input length is not a multiple of 3 bytes
  • Large files inflate size by roughly 33% — avoid Base64 for big binary transfers when raw bytes are supported

Security Considerations

Anyone can decode Base64 instantly. Never use it to hide passwords, API keys, or sensitive data. For secrets, use proper encryption and key management.

Developer Tips

  • Browser: btoa() for ASCII; use TextEncoder first for Unicode
  • Node.js: Buffer.from(str).toString('base64')
  • Python: base64.b64encode(data)

Frequently asked questions

Does Base64 encoding compress data?

No. Base64 increases size by about 33% because it represents 3 bytes as 4 ASCII characters.

Can I encode binary files with this tool?

Yes. Use Upload file to select an image, PDF, or other binary file — bytes are read locally in your browser (up to 5 MB) and never uploaded. You can also paste UTF-8 text as before.

Why does my output end with = or ==?

Padding characters align the output to a multiple of 4 characters. They are normal and required for standard Base64.