Base64 Encode & Decode
Paste text or a Base64 string below to encode or decode it instantly. Works with UTF-8 text, URLs, JSON snippets and more — everything runs locally in your browser, nothing is uploaded anywhere.
Type or paste text above, then click "Encode" or "Decode" depending on what you need.
Frequently asked questions
Is my data uploaded to a server?
No. All encoding and decoding happens locally in your browser via JavaScript; nothing is sent to a server.
What is Base64 used for?
Base64 is commonly used to embed binary data (images, files) inside text formats like JSON, XML, HTML or email attachments, and to safely transmit data over text-based protocols.
Why do I get an error when decoding?
It means the text you pasted isn't valid Base64 — it may contain characters outside the Base64 alphabet (A–Z, a–z, 0–9, +, /, =) or have incorrect padding.
What is URL-safe Base64?
Standard Base64 uses + and / which have special meaning in URLs and filenames. URL-safe Base64 (RFC 4648 §5) replaces them with - and _ and omits padding, making the result safe to use directly in URLs, filenames or JWT tokens.