Question 1

What is Base64 encoding and when should I use it?

Accepted Answer

Base64 encodes binary data into ASCII text using 64 printable characters. Use it when you need to transmit binary data (like images or files) over systems designed to handle text, such as email (MIME) or embedding data in JSON. Base64 is not encryption — it is easily reversible by anyone.

Question 2

What is a JWT token and how do I decode it?

Accepted Answer

A JWT (JSON Web Token) is a compact, URL-safe way to represent claims between two parties. It consists of three Base64-encoded parts separated by dots: header, payload, and signature. Decoding a JWT reveals the claims (user ID, expiry, roles, etc.) but does not verify the signature — you need the secret key for verification.

Question 3

What is the difference between URL encoding and Base64?

Accepted Answer

URL encoding (percent-encoding) converts characters not allowed in URLs into a % followed by two hex digits, used to safely include special characters in URLs. Base64 converts arbitrary binary data into 64 ASCII characters for text-safe transmission. They serve different purposes and are not interchangeable.

⇄ Encoding & Decoding

Base64 Encode / Decode

Hex Encode / Decode

URL Encode / Decode

HTML Entities Encode / Decode

JWT Decoder