Encoding & Hashing/Base64 Encoder/Decoder
Base64 Encoder & Decoder
Instantly encode plain text to Base64 or decode a Base64 string back to text. Supports standard and URL-safe variants. Nothing leaves your browser.
🔒All encoding happens locally in your browser. Nothing leaves your device.
39 chars · 41 bytes
What is Base64?
Base64 is an encoding scheme that converts binary data into a string of 64 printable ASCII characters (A–Z, a–z, 0–9, +, /). It is widely used to safely embed binary data — images, files, or arbitrary bytes — inside text-based formats like JSON, XML, HTML, and email headers.
The URL-safe variant replaces + with - and / with _ and strips padding (=) so the output can be safely placed in a URL without percent-encoding. JWTs use this variant.
FAQ
Is my data sent anywhere?
No. Encoding and decoding are done entirely in your browser using the browser's built-in btoa and atob APIs. Nothing leaves your device.
Does Base64 encrypt my data?
No. Base64 is an encoding scheme, not an encryption algorithm. The encoded string can be trivially decoded by anyone who has it. Do not use Base64 as a security measure.
Why does the output end with = or ==?
Base64 groups input bytes in sets of three and encodes each group as four characters. If the input length isn't a multiple of three, padding characters (=) are added to make the output length a multiple of four. Enable URL-safe mode to strip them.
Is there a size limit?
Text-file uploads are capped at 20 MB. For very large files you may prefer a command-line tool (base64 on macOS/Linux, certutil -encode on Windows).
Working with JWTs? Try the JWT Decoder →