Base64 Encode / Decode
Convert Base64
How to Use This Base64 Encode / Decode Tool
API docs say "send the payload Base64-encoded" and suddenly you are pasting opaque strings into Slack wondering if you broke something. Base64 is everywhere—email attachments, JWT tokens, data URLs—and encoding or decoding by hand is not realistic.
- Select Action. Choose Encode (Text → Base64) or Decode (Base64 → Text).
- Paste Input Data into the text area.
- Press Encode or Decode. The result appears in the output field.
- Copy Result with the copy button when ready.
For URL-specific encoding (spaces as %20), use URL Encode / Decode. For generating API keys or passwords, try the Password Generator.
Base64 Formulas and Practical Applications
Base64 maps every 3 bytes of input to 4 ASCII characters from a 64-character alphabet (A–Z, a–z, 0–9, +, /). Padding with = fills incomplete groups. Output is roughly 33% longer than the original binary—trade space for transport safety through text-only channels.
Encoding uses UTF-8 before conversion, so accented characters and emoji survive a round trip. Decoding validates the alphabet and padding before reversing to text. Everything runs in your browser—nothing uploads to a server.
Frequently Asked Questions
What is Base64 used for?
Base64 encodes binary data as text safe for JSON, XML, email, and URLs. Common uses include embedding small images in HTML (data URLs), transmitting file chunks in APIs, and encoding credentials in Basic Auth headers.
Is Base64 encryption?
No. Base64 is encoding—fully reversible by anyone who sees the string. Never treat it as security. Use proper encryption (TLS, AES) for sensitive data.
Why does decoding fail?
Invalid characters, missing padding (=), or truncated strings cause decode errors. Ensure you copied the complete Base64 string without line breaks or extra whitespace unless the format expects MIME wrapping.
Does this tool support Unicode and emoji?
Yes. Encoding uses UTF-8 before Base64 conversion, so accented characters and emoji survive a round trip when the input is valid text.
Is my input sent to a server?
No. Encode and decode run entirely in your browser. Nothing is uploaded or logged by RapidRatio.