About Encoding Tools
Base64 Encoding
Base64 is a binary-to-text encoding scheme that represents binary data in ASCII string format. It's commonly used for encoding images in CSS/HTML, transferring data over text-based protocols, and storing complex data in URLs or cookies.
URL Encoding
URL encoding (also known as percent-encoding) converts characters into a format that can be transmitted over the Internet. Special characters, non-ASCII characters, and reserved characters are replaced with a percent sign followed by two hexadecimal digits.
JWT (JSON Web Tokens)
JWT is a compact, URL-safe means of representing claims between two parties. It consists of three parts: header, payload, and signature. JWTs are widely used for authentication and information exchange in web applications.
Privacy First
All encoding and decoding operations are performed entirely in your browser. Your data never leaves your device, ensuring complete privacy and security.
Frequently Asked Questions
What is Base64 encoding and how does it work?
Base64 encoding converts binary data into a 64-character ASCII text format using characters A-Z, a-z, 0-9, +, and /. It takes 3 bytes of binary data and converts them into 4 ASCII characters, making binary data safe for transmission over text-based protocols like email and HTTP.
How do I convert an image to Base64?
Use our Base64 encoder: 1) Click "File Upload" tab, 2) Drag and drop your image or click to browse, 3) The tool automatically converts it to a Base64 string. Enable "Include data URL prefix" to get the full data URI for direct use in HTML/CSS.
What characters need to be URL encoded?
Characters that must be URL encoded include: spaces (%20), ampersand & (%26), equals = (%3D), question mark ? (%3F), plus + (%2B), forward slash / (%2F), hash # (%23), and percent % (%25). Non-ASCII characters like accented letters and emojis must also be encoded.
What is the difference between encodeURI and encodeURIComponent?
encodeURI() encodes a complete URL, preserving characters like :, /, ?, and # that have special meaning in URLs. encodeURIComponent() encodes everything except alphanumeric characters, making it suitable for encoding URL parameters. Use encodeURIComponent() for query string values.
How do I decode a JWT token?
Paste your JWT token into our decoder and click "Decode JWT". You'll see the decoded header (with algorithm info), payload (containing claims like user ID and expiration), and signature. Our tool shows if the token is expired and explains common claims.
What does JWT exp claim mean?
The JWT "exp" (expiration) claim indicates when the token expires, stored as a Unix timestamp (seconds since January 1, 1970). After this time, the token should be considered invalid. Our decoder shows both the timestamp and human-readable date.
Is Base64 encoding the same as encryption?
No, Base64 is NOT encryption. It's an encoding scheme that converts binary to text - anyone can decode it without a key. For sensitive data, use proper encryption (AES, RSA) before Base64 encoding if you need to transmit encrypted data as text.
Why does Base64 increase file size?
Base64 increases data size by approximately 33% because it converts every 3 bytes of binary data into 4 ASCII characters. For example, a 1MB file becomes about 1.37MB when Base64 encoded. This overhead is the tradeoff for text-safe transmission.