Encode text to Base64 or decode Base64 back to plain text instantly. Supports full UTF-8 characters including emojis. No data is stored or transmitted — everything runs in your browser.
Base64 is a binary-to-text encoding scheme that represents binary data using a set of 64 printable ASCII characters (A–Z, a–z, 0–9, +, /). It was designed to safely transmit binary data through systems that only support text, such as email (MIME), URLs, and JSON/XML payloads.
Base64 encoding works by taking every 3 bytes (24 bits) of input and splitting them into 4 groups of 6 bits, each mapped to one of the 64 characters. If the input length isn't divisible by 3, the output is padded with = characters. This process increases the data size by approximately 33%.
Email attachments (MIME). Email protocols (SMTP) were designed for 7-bit ASCII text. Binary files like images and PDFs must be Base64-encoded to travel safely through email servers. Every email attachment you've ever sent uses Base64 under the hood.
Data URIs in web development. Small images and fonts can be embedded directly in HTML/CSS using data: URIs with Base64-encoded content, eliminating extra HTTP requests and improving page load speed for small assets.
API payloads and tokens. REST APIs commonly use Base64 to encode binary data within JSON payloads. JWTs (JSON Web Tokens) use a URL-safe variant called Base64URL to encode the header and payload segments.
Basic HTTP authentication. The HTTP Authorization: Basic header transmits credentials as a Base64-encoded username:password string. Note: this provides encoding, not encryption — always use HTTPS alongside it.
No. Base64 is encoding, not encryption. It provides zero security — anyone can decode a Base64 string instantly. It is designed for data transport compatibility, not confidentiality. Never use Base64 to "hide" sensitive information like passwords, API keys, or personal data. For actual security, use proper encryption (AES, RSA) or hashing (SHA-256, bcrypt).
Yes. This tool runs 100% in your browser using native JavaScript encoding functions. No data is transmitted to any server, stored in any database, or logged anywhere. Conversion happens in real-time as you type — entirely client-side. You can verify this by disconnecting from the internet.