Base64 Encoder & Decoder
Encode plain text to Base64 or decode Base64 back to text — entirely in your browser.
How Base64 Encoding works
Base64 encodes binary data as a sequence of printable ASCII characters, using 64 symbols (A–Z, a–z, 0–9, +, /). It increases data size by approximately 33% but ensures safe transmission over text-based channels. Common uses include encoding images in HTML/CSS data URIs, transmitting binary data in JSON APIs, and encoding credentials in HTTP Basic Authentication headers. All processing happens locally — nothing is sent to a server.
Why the Base64 Encoder / Decoder is Useful
Base64 is everywhere in web development — you just don't always see it. It's how images get embedded in HTML as data URIs, how API credentials are passed in HTTP Basic Authentication headers, and how binary data gets transmitted safely over text-only channels like email or JSON APIs. This tool converts text to Base64 and back, entirely in your browser, with no data ever leaving your device.
Key Features
- One-click encoding: Convert any plain text or string to Base64 instantly
- One-click decoding: Turn any valid Base64 string back to plain text
- Unicode support: Handles accented characters, emoji, and non-Latin scripts correctly
- 100% browser-based: No server involved — safe for encoding sensitive strings or credentials
- Copy to clipboard: One-click copy for the encoded or decoded result
Real-Life Use Cases
- Developers encoding API credentials for HTTP Basic Authentication:
Authorization: Basic base64(username:password) - Embedding small images as data URIs in HTML or CSS to eliminate extra image HTTP requests
- Passing binary data inside JSON API payloads that only support text values
- Decoding Base64-encoded JWT token headers and payloads to inspect their contents
- Encoding email attachment file names or content for MIME-encoded messages
Who Can Use This Tool
Frontend and backend developers, DevOps engineers, QA testers, and security researchers. Also useful for computer science students learning about encoding schemes, or anyone who encounters a Base64 string and wants to know what it says.
Tips & Best Practices
- Base64 increases data size by approximately 33% — for large images, serving them as actual image files is more efficient
- JWT tokens are Base64-encoded but not encrypted — you can decode the header and payload, but not verify the signature without the secret key
- Base64 is encoding, not encryption — never use it to hide sensitive data like passwords
- Always use HTTPS when transmitting Base64-encoded credentials, even though the encoding itself adds no security