Base64 Encoder & Decoder

How to use Base64 Encoder & Decoder

1. Choose Encode or Decode using the tabs at the top.
2. Paste your text into the input area.
3. The output updates instantly — no button press needed.
4. Click Copy to grab the result, or Swap to move the output to the input for chaining conversions.

Common use cases

• Basic HTTP authentication. HTTP Basic auth expects a base64-encoded 'user:password' string. Encode your credentials here to test API endpoints from curl or Postman.
• Data URLs for images. Base64-encode small images to embed them directly in HTML/CSS via `data:image/png;base64,…` — no separate HTTP request.
• JWT token inspection. JWTs are three base64url-encoded sections joined by dots. Decode the middle section to see the payload (use our JWT decoder for a friendlier view).
• Storing binary in JSON. JSON does not natively hold binary bytes. Encoding as base64 lets you attach small files (icons, PDFs) inside JSON APIs.

Tips

• Base64 adds ~33% overhead — a 1 MB file encodes to ~1.37 MB of text. Not efficient for large payloads.
• There are two flavors: standard (uses +/) and URL-safe (uses -_). This tool uses standard base64. For JWTs and URL params, our JWT decoder handles URL-safe variants.
• Base64 is NOT encryption. It hides text from a casual glance but anyone can decode it in a second. Never use it as security.
• Whitespace and line breaks inside base64 are usually tolerated by decoders — safe to paste multi-line encoded strings.

Troubleshooting

Decoded text has garbage characters.

The source might be encoded with a different character set (Latin-1 rather than UTF-8), or you might be decoding data that isn't text at all — like a binary image.

'Invalid Base64' when the string looks correct.

Check for hidden trailing characters (newline, non-breaking space) added by copy-paste. Trim the string or retype the last character.