Encode text and files to Base64 format
Base64 encoded data will appear here
A Base64 encoder/decoder converts binary data into a safe, ASCII‑only string so it can pass through systems that expect text—email bodies, JSON, query strings, and data URIs. Use this online Base64 converter to encode files, images, and arbitrary bytes, or to decode Base64 strings back to their original form. Base64 is not encryption; it’s a reversible transport encoding that expands size by ~33%.
The algorithm groups input into 3‑byte chunks (24 bits), then maps them to four 6‑bit values using a 64‑character alphabet (A–Z, a–z, 0–9, +, /). If input length isn’t a multiple of 3, = padding characters align the output to a 4‑character boundary. A URL‑safe variant replaces +/ with -_ and may omit padding. This tool supports both, so you can round‑trip strings in web contexts and APIs.
Encode a small PNG or SVG to embed as a data URI in CSS or HTML; convert a cryptographic random byte buffer to a Base64 token for debugging; decode a Base64 string from a JSON payload to recover an attachment. Example: data:image/png;base64,iVBORw0KGgo... can be pasted into a browser address bar to display an inline image.
For text, we read and write UTF‑8 to preserve international characters. For files, the browser processes data locally without uploading it, preserving privacy. Paste text to encode/decode, or drop a file and choose output options. Copy the result to clipboard or download it as a .txt file for sharing.
Base64 increases size by roughly one third, which can impact bandwidth and memory on large assets. Avoid using it for bulky images when caching static files is possible. Since Base64 is reversible, never treat it as a security control—use cryptography for confidentiality (encryption) and integrity (signatures or MACs).
Base64 is a practical tool for small assets, data URLs, and debugging encodings. Keep security and size trade‑offs in mind when choosing it for production.