🔐 Encode · Decode · URL-safe · Free

Base64
Encoder & Decoder

Encode text to Base64 or decode Base64 back to plain text instantly. Supports standard Base64 and URL-safe Base64. Live conversion as you type.

🔒 Encode to Base64
🔓 Decode from Base64
Standard Base64 URL-safe Base64
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Free Base64 Encoder and Decoder Online

ExperToolBox's Base64 encoder and decoder converts text to and from Base64 encoding instantly as you type. It supports both standard Base64 (using + and / characters) and URL-safe Base64 (using - and _ instead, making the output safe to include in URLs without encoding).

Base64 is an encoding scheme that converts binary data (or text) into a string of ASCII characters. It's widely used in web development, email systems, data storage and transmission wherever binary data needs to be handled as text.

What is Base64 used for?

Data URIs: Images and other binary files can be embedded directly in HTML or CSS using Base64-encoded data URIs (data:image/png;base64,...). This eliminates extra HTTP requests but increases file size by about 33%.

JWT tokens: JSON Web Tokens use Base64 URL encoding for the header and payload sections. If you decode a JWT's middle section, you'll see the claims in plain JSON.

HTTP Basic Auth: The Authorization header in HTTP Basic authentication encodes the username:password pair in Base64.

Email attachments: The MIME standard uses Base64 to encode binary attachments in email messages, which are text-based protocols.

API keys and credentials: Many systems distribute API keys and credentials as Base64-encoded strings for easier handling.

Standard Base64 vs URL-safe Base64

Standard Base64 uses the characters A-Z, a-z, 0-9, + and /. The + and / characters have special meaning in URLs and must be percent-encoded when used in query strings, which creates longer and less readable URLs. URL-safe Base64 (also called Base64url) replaces + with - and / with _, making the output safe to use directly in URLs and filenames without encoding.

Frequently Asked Questions

Is Base64 encryption?
No. Base64 is encoding, not encryption. Anyone can decode Base64 without any key or password — it provides no security whatsoever. Never use Base64 to "hide" sensitive data. For actual encryption, use AES, RSA, or other proper cryptographic algorithms.
How much does Base64 increase file size?
Base64-encoded data is approximately 33% larger than the original. This is because Base64 represents every 3 bytes of input as 4 ASCII characters. For images embedded as data URIs, this size increase is the trade-off for eliminating an HTTP request.
Why does my Base64 end with == or =?
Base64 encodes data in 3-byte chunks. If the input length isn't a multiple of 3, padding characters (=) are added to make the output length a multiple of 4. One = means one byte of padding was needed; == means two bytes.
Can I Base64 encode binary files with this tool?
This tool works with text input only. For encoding binary files (images, PDFs, etc.) to Base64, you need a tool that accepts file uploads and processes the binary data directly.

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