How to use it
- Paste text or Base64.
- Click Encode or Decode.
- Copy the result.
Why use it
- Convert text to Base64 in one click.
- Decode values from URLs, headers, and APIs.
- Handles Unicode and emoji correctly.
- Runs fully offline for privacy.
- Simple, fast, and free.
What is Base64?
Base64 is an encoding scheme that converts binary data into an ASCII string using a 64-character alphabet (A–Z, a–z, 0–9, +, /, and = for padding). Because the result contains only safe text characters, Base64 data can be transported through text-only systems without corruption.
Why Base64 is everywhere
- Data URIs: embedding small images directly in HTML or CSS as
data:image/png;base64,...avoids extra HTTP requests. - API payloads: binary uploads and downloads are sent as Base64 in JSON where raw bytes are not supported.
- Email attachments: the MIME standard encodes attachments as Base64 so they survive text-based email protocols.
- Token formats: JWTs and similar tokens Base64-encode their header and payload segments.
Base64 vs. hexadecimal
| Base64 | Hex | |
|---|---|---|
| Alphabet | 64 chars | 16 chars (0–9, a–f) |
| Size overhead | ~33% larger | 100% larger |
| Best for | Transmitting binary in text | Readable debugging, checksums |
A common gotcha: Base64 is an encoding, not encryption. Anyone can decode it. Do not use Base64 to hide sensitive data. Use it only where text transport is needed.