Encoders & Decoders
Encode and decode data between formats. — 5 tools available.
Encoding tools convert data between representation formats used across web development, cryptography, and data transfer. Base64 encoding is required for embedding binary data in JSON, data URIs, or sending attachments over email (MIME). URL percent-encoding ensures query string values containing special characters — spaces, ampersands, Unicode — are transmitted safely. Cryptographic hashing with MD5, SHA-1, or SHA-256 lets you verify file integrity, generate checksums, or store password digests without keeping plaintext. The JWT Decoder lets you inspect JSON Web Tokens by decoding the Base64url-encoded header and payload to read claims like expiration time, issuer, and subject — all without transmitting the token to any server. Every encoder and decoder here runs entirely in your browser using standard Web APIs like btoa(), atob(), encodeURIComponent(), and the Web Crypto API. Your data never leaves your device, making these tools safe for working with API keys, authentication tokens, and private configuration values.
5 Encoders & Decoders Tools
Base64 Encoder & Decoder
Encode text to Base64, or decode Base64 back to plain text. Supports full UTF-8.
URL Encoder & Decoder
Encode or decode URL components and query strings.
Hash Generator
Generate MD5, SHA-1, and SHA-256 hashes from any text using your browser's built-in crypto.
JWT Decoder
Decode and inspect JSON Web Tokens — view header, payload, and expiry status instantly.
Number Base Converter
Convert numbers between binary, decimal, octal, and hexadecimal. Includes two's complement representation and ASCII character mapping for developer reference.
Frequently Asked Questions
What is the difference between encoding and encryption?
Encoding transforms data into a different format for compatibility or transport (like Base64 or URL encoding) using a publicly known scheme — anyone can decode it without a key. Encryption transforms data to protect confidentiality using a secret key — only someone with the correct key can decrypt it. Encoding is not a security measure. Never use Base64 or URL encoding to protect sensitive data.
What is Base64 encoding used for?
Base64 encodes binary data as ASCII text so it can be safely embedded in text-only formats. Common uses include data URIs in HTML/CSS (embedding small images inline), email attachments (MIME encoding), JSON Web Tokens (JWTs), HTTP Basic Authentication headers, and embedding binary payloads inside JSON or XML documents. Base64 increases data size by approximately 33%.
What is URL encoding and when do I need it?
URL encoding (percent-encoding) replaces characters that have special meaning in URLs — like spaces, ampersands, and question marks — with percent-hex sequences (e.g., space becomes %20). You need URL encoding whenever user-supplied values appear in URL query parameters, path segments, OAuth redirect URIs, or form submissions to prevent the URL structure from breaking.