Base64 Encoder / Decoder
Base64 encode decode online for text or files. Use this base64 to text converter, encode a file to Base64, or run the base64 string decoder, all processed locally in your browser.
Options
Replaces + with - and / with _ so the resulting string can be safely used inside a web URL.
About Base64 Encoder / Decoder
This base64 encode decode online tool is built for developers who frequently convert data formats for APIs, CSS embedding, or data transfer. It supports plain text, full files, and maintains full compatibility with UTF-8 characters, including emojis and other special symbols.
Everything runs on the client side using your browser's native Web APIs, so your data stays private. Whether you are decoding a JSON Web Token payload, encoding a file to Base64 for a data URI, or running the base64 string decoder on a binary backup, nothing is ever uploaded to a remote server.
How to Use
- Choose Text Input to paste raw text or Base64, or File Input to upload a file.
- Select Encode to Base64 or Decode from Base64 depending on the direction of the conversion.
- Enable URL-Safe Mode if the output needs to be placed inside a URL or query string.
- Review the output, then click Copy Output or Download Output to save the result.
Common Use Cases
Embedding Images
Convert small images into Base64 strings to embed them directly into HTML or CSS, reducing HTTP requests and speeding up page loads.
API Authentication
Basic HTTP authentication requires credentials formatted as username:password and encoded in Base64 before being sent in the authorization header.
JSON Web Tokens (JWT)
The header and payload sections of a JWT are encoded using URL-safe Base64. Decode these segments here to inspect the token's claims.
Data Transfer
XML and JSON do not natively support binary data. Converting files like PDFs or ZIPs to Base64 lets them travel safely inside text-based payloads.
Who Should Use This Tool
- Backend developers who need to encode file to base64 for embedding in a JSON or XML payload.
- Frontend engineers who use a base64 to text converter to inspect data URIs or JWT segments.
- Security researchers who need a quick base64 string decoder while reviewing captured traffic.
- Students and educators learning how binary-safe text encoding works in practice.
Privacy first. Every conversion runs locally in your browser tab. No text or file you provide to this base64 converter free tool is ever uploaded, logged, or stored on a server.