Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 strings online — free, instant, no install. Full Unicode support. See both results side by side.
Input
Base64 Encoded
Base64 Decoded
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Frequently Asked Questions
What is Base64?
Base64 is an encoding method that represents binary data using only ASCII characters (letters, digits, +, and /). It is used to safely transmit binary data in environments that only allow text, such as emails, APIs, and HTML.
When is Base64 used?
Common use cases include embedding images directly in HTML <img> tags, including file data in API requests, and encoding credentials in the HTTP Basic Auth header (Authorization).
What is the difference between URL-safe Base64 and standard Base64?
Standard Base64 uses the + and / characters, which have special meanings in URLs and can cause issues. URL-safe Base64 replaces + with - and / with _, so the string can be safely used in URLs.
How much does the file size increase after Base64 encoding?
The size increases by about 33%. Three bytes of original data are converted into four ASCII characters. Keep this in mind when embedding images as Base64 in HTML, as the file size will be noticeably larger.
Can Korean characters and emojis be Base64 encoded?
Yes, since the data is first encoded as UTF-8 and then converted to Base64, Korean characters, emojis, and special characters can all be handled. When decoding, the text is automatically restored as UTF-8.
What is Base64?
- Encoding: Converts plain text into a Base64 string made up of 64 safe characters (A–Z, a–z, 0–9, +, /). Used to safely transmit data in text-only environments like email, APIs, and URLs.
- Decoding: Restores a Base64 string back to its original text. If you receive data that looks like random letters and numbers, try decoding it to reveal the actual content.
Features
- Live Conversion: Results update as you type
- Full Unicode Support: Works with any language, emoji, and special characters
- Side-by-Side View: See both encoded and decoded results at once
How to Use
- Type or Paste: Enter text to encode or a Base64 string to decode
- Check Results: Both results appear instantly in real time
- Copy: Click Copy on whichever result you need
Use Cases
- API Auth: Used in HTTP Basic auth headers and JWT tokens
- Data Transfer: Safely encode data for URLs
- Email: MIME encoding for attachments and headers
- Debugging: Quickly decode Base64 data to inspect its contents
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