Base64 Encoder & Decoder
Encode plain text to Base64 or decode Base64 strings back to text — instantly in your browser. No data sent to any server.
What is Base64 Encoding?
Base64 is a binary-to-text encoding scheme that converts binary data into an ASCII string format using 64 printable characters. It is widely used to encode data that needs to be stored or transferred over media that are designed to handle text — such as email, URLs, HTML and JSON.
Base64 encoding is not encryption — it is purely an encoding format. The encoded string can be decoded back to the original data by anyone. It is used for safe transport of data, not for security.
When Do Developers Use Base64?
API Authentication
HTTP Basic Auth encodes credentials as Base64 — username:password → Base64 string in the Authorization header.
Email Attachments
MIME protocol encodes binary email attachments as Base64 for safe transmission over text-based SMTP.
Inline Images
Embed images directly in HTML or CSS as Base64 data URIs — no separate HTTP request needed.
JWT Tokens
JSON Web Tokens use Base64URL encoding for header and payload sections — easily decoded for inspection.
Data Storage
Store binary data like images or files in databases or JSON fields using Base64 encoding.
URL Safe Data
Encode special characters in URLs using Base64 to avoid encoding issues in query parameters.
Base64 Encoding vs Encryption
| Factor | Base64 Encoding | Encryption |
|---|---|---|
| Purpose | Safe data transport | Data security |
| Reversible | ✅ Yes — by anyone | ✅ Yes — only with key |
| Key required | ❌ No key needed | ✅ Secret key required |
| Size increase | ~33% larger | Varies |
| Use for passwords | ❌ Never — not secure | ✅ Yes (with hashing) |
Common Use Cases
- Decoding JWT token payloads for inspection
- Testing HTTP Basic Auth headers
- Encoding images for inline HTML/CSS use
- Encoding binary data for JSON API fields
- Debugging API requests and responses
- Inspecting MIME encoded email content