Base64 Encoder / Decoder — Free Online Tool

Plain text Base64 output

What is Base64?

Base64 is an encoding scheme that converts binary data into a string of ASCII characters. It uses 64 printable characters (A–Z, a–z, 0–9, +, /) so that binary content can be safely transmitted over text-based channels like email, JSON payloads, or HTML attributes.

Common uses

Embedding images or fonts directly in CSS or HTML as data: URIs
Encoding credentials in HTTP Basic Authentication headers
Passing binary data in JSON API requests or responses
Reading JWT tokens — the header and payload sections are Base64-encoded

How to use

Paste any plain text into the Encode tab and press Encode. To reverse the process, switch to the Decode tab and paste a Base64 string. Everything runs locally in your browser — your data is never sent to a server.