Base64 encodes binary data as readable ASCII text using 64 symbols (A - Z, a - z, 0 - 9, +, /) with optional = padding. This tool focuses on text and safely converts it to/from UTF-8 so non-ASCII characters survive a full round-trip. π¦
What you can do
- Encode text into Base64 for transport, storage, or embedding.
- Decode Base64 strings back into readable UTF-8 text.
- Swap fields to quickly chain multiple conversions.
How it works
- Encode: Text β UTF-8 bytes β binary string β Base64 (via
btoa) - Decode: Base64 β binary string (via
atob) β UTF-8 bytes β Text
Base64 quick reference
| Feature | Description | Notes |
|---|---|---|
| Alphabet | A - Z a - z 0 - 9 + / | 64 symbols total |
| Padding | = |
May be one or two characters |
| Encoding size | ~33% larger than input | 4 chars per 3 bytes |
| Character safety | ASCII-only output | Safe for text transports |
Buttons
- Encode Β»: Convert input text to Base64 and show it on the right.
- Decode Β»: Convert Base64 on the left back to readable text.
- Β« Swap Β»: Swap left/right fields to continue in the opposite direction.
- Copy Result π: Copy the right textarea to your clipboard.
- Erase: Clear both fields.
- Demo: Fill the input with a short example.
How to use
- Enter text or Base64 into the Input field.
- Click Encode to get Base64, or Decode to get text.
- Use Swap to move the result back to the input for another step.
- Click Copy Result to copy the output.
Examples
- Hello β Base64:
SGVsbG8= - π (UTF-8) β Base64:
8J+YgA== - β OK β Base64:
4pyTIM6PTw==
Tips
- Base64 is not encryption - it only encodes data. Anyone can decode it π
- If decoding fails, check for missing padding (
=) or invalid characters. - For URLs, APIs, or JWTs, you may need URL-safe Base64.
Notes & limitations
- This tool is designed for text. For binary files, use a dedicated file-to-Base64 converter.
- URL-safe Base64 replaces
+with-and/with_and may omit padding. - Very large inputs may be slow or memory-intensive in the browser.
