Base64 Encode & Decode
Encode or decode Base64 strings instantly in your browser. Supports text and data URIs. No signup, no install. Free forever.
What is Base64 Encode & Decode?
Base64 encoding converts binary or text data into a safe ASCII string representation — commonly used for embedding images in CSS data URIs, passing binary data through JSON, and encoding authentication credentials. This tool encodes plain text to Base64 or decodes Base64 back to readable text instantly, with no server involved.
Developers working with APIs, email systems, JWTs, or browser storage reach for a Base64 tool regularly. Whether you're encoding a file for a data URI, decoding a JWT payload to inspect its claims, or troubleshooting a Basic Auth header, you need a fast and reliable tool that handles the conversion without copying code into a console.
Everything runs in your browser — your data never leaves your device. No account needed, no sign-up, no server upload. Just paste and go.
How to use
Frequently asked questions
Yes. The encoding and decoding happen entirely in your browser using JavaScript's built-in functions. Nothing is transmitted to any server.
No server limit. Very large inputs are only constrained by your browser's available memory.
No. All useTool tools are free with no sign-up required.
This tool handles text input. For encoding image files as Base64 data URIs, see our Image Tools category.
Common uses include embedding images in CSS or HTML (data URIs), encoding binary data in JSON payloads, Basic Auth headers (username:password), and storing binary data in localStorage.