Text Base64 Encoder/Decoder
File to Base64 / Base64 to File
Upload a file to convert to Base64
Paste Base64 to download as file
What is Base64 Encoding?
Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It uses a set of 64 characters (A-Z, a-z, 0-9, +, /) to encode data. Base64 is commonly used in email, data URLs, and transferring binary data over text-based protocols like HTTP.
How to Use
- Enter your plain text in the left textarea.
- Click Encode to convert to Base64.
- Or paste Base64 in the right textarea and click Decode.
- Use the file section to convert files to/from Base64.
Features
- Full UTF-8 and Unicode support
- File to Base64 and Base64 to file conversion
- Auto-detection of Base64 input
- Copy to clipboard with one click
- Character count for both sides
- 100% client-side processing
Common Use Cases
Data URLs
Embed images, fonts, or other assets directly in HTML/CSS using Base64 data URLs instead of linking to external files.
Email Attachments
Email systems use Base64 to encode binary attachments into text format that can travel through SMTP servers.
API Authentication
HTTP Basic Authentication encodes credentials in Base64 format. Many APIs use Base64 for token transmission.
JSON Payloads
Embed binary data in JSON responses by encoding it as Base64 strings, since JSON cannot directly represent binary data.
Base64 Character Table
| Value | Char | Value | Char | Value | Char |
|---|---|---|---|---|---|
| 0-25 | A-Z | 26-51 | a-z | 52-61 | 0-9 |
| 62 | + | 63 | / | pad | = |
FAQ
What characters does Base64 use?
Base64 uses A-Z, a-z, 0-9, +, and / characters. The = character is used for padding at the end of the encoded string. The encoding uses exactly 64 characters from the ASCII set, which is where the name comes from.
Is Base64 encryption?
No, Base64 is an encoding, not encryption. It provides no security and can be easily decoded by anyone. It is simply a way to represent binary data as text. For security, use proper encryption algorithms like AES.
Why does Base64 increase file size?
Base64 encoding increases the data size by approximately 33% because every 3 bytes of binary data are encoded as 4 ASCII characters. This overhead is the trade-off for having a text-safe encoding format.
Is my data sent to a server?
No, all encoding and decoding happens entirely in your browser using JavaScript. No data is transmitted to any server, making it safe for sensitive information.