Base64 Encoder Online
Encode text strings into Base64 format instantly. 100% private and free.
Key Capabilities
Encodes both text and binary files
Handles plain text input and binary file upload. Text is encoded using UTF-8 by default.
URL-safe Base64 variant
The URL-safe variant replaces + and / with - and _, producing strings safe for URLs and JWT tokens.
Generates inline data URIs for images
Upload an image and the tool outputs a complete CSS-ready data URI.
How to Use
Choose input type and provide content
Select Text for encoding strings or File for encoding binary files.
Select encoding variant
Choose standard Base64 for most uses, or URL-safe Base64 for URLs and JWT tokens.
Copy the encoded output
Use the copy button. Line breaks are stripped automatically when copying.
Common Use Cases
- Frontend developers embedding fonts in CSSA web developer can Base64-encode a custom icon font and insert it as a data URI in CSS.
- API developers encoding authentication credentialsA developer can Base64-encode the username:password string for HTTP Basic Authentication headers.
- Mobile developers encoding images for JSON payloadsA mobile app developer can encode an image file for a REST API that expects Base64 in JSON.
Frequently Asked Questions
What is Base64 encoding?
Base64 converts binary or text data into a 64-character ASCII representation (A-Z, a-z, 0-9, +, /). It's used to safely transmit binary data through text-only channels like email, JSON payloads, HTML data URIs, and HTTP headers.
Who uses this tool professionally?
Developers encode API authentication credentials for HTTP Basic Auth headers. Email system administrators encode attachment data for MIME email formatting. Frontend developers create Base64 data URIs for embedding small images directly in CSS and HTML.
Does it handle binary data?
This tool encodes text strings to Base64. For binary file encoding (images, PDFs), the file should first be read as a binary buffer. The tool handles all UTF-8 text including international characters and special symbols.
Is my data kept private?
Yes. All encoding happens locally in your browser. Sensitive data like passwords and tokens are never transmitted to any server.
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