Free Online Encoding & Decoding Tools
Encode, decode, hash, and convert data securely in your browser. Base64, URL encoding, HTML entities, JWT tokens, and more.
Base64 Encode & Decode
Encode and decode Base64 strings and files online. Supports UTF-8, file drag-and-drop, and image preview. 100% browser-based, no data uploaded.
JWT Decoder
Decode and inspect JSON Web Tokens instantly. Color-coded header, payload, and signature. Check token expiration, issuer, subject, and claims. Free, private, browser-based.
UUID & Hash Generator
Generate UUID v4 identifiers and compute MD5, SHA-1, SHA-256, SHA-512 hashes instantly. Bulk UUID generation, uppercase/lowercase options. Free, browser-based.
URL Encode & Decode
Encode or decode URL components and full URIs instantly. Supports encodeURIComponent and encodeURI modes. Free, browser-based, no data sent anywhere.
HTML Entity Encoder & Decoder
Convert special characters to HTML entities and back. Supports named and numeric entities. Free, fast, browser-based.
Password Generator
Generate strong, random passwords with configurable length, character types, strength meter, and bulk generation. Cryptographically secure. Free, browser-based.
Image to Base64 Converter
Convert images to Base64 data URIs for CSS, HTML, or APIs. Supports PNG, JPG, GIF, SVG, WebP. Free, browser-based, no uploads.
Number Base Converter
Convert between binary, octal, decimal, and hexadecimal number systems instantly. Shows bit info. Free, browser-based.
Why encoding matters
Encoding transforms data from one format to another for safe transmission, storage, or display. URLs cannot contain spaces or special characters, so they must be percent-encoded. HTML pages need entities to display characters like < and & without breaking the markup. Binary files must be Base64-encoded to travel over text-based protocols like email and JSON.
Base64 encoding
Base64 Encode & Decode handles both text and file input with proper UTF-8 support. The Image to Base64 tool is specifically built for embedding images as data URIs in CSS and HTML, useful for reducing HTTP requests or inlining small icons.
URL and HTML encoding
The URL Encoder supports both encodeURIComponent (for query parameters) and encodeURI (for full URIs). The HTML Entity Encoder converts special characters to named or numeric entities, with a quick reference grid for common symbols.
Security tools
The JWT Decoder inspects JSON Web Tokens without sending them to a server, which is critical since JWTs often contain authentication credentials. The UUID & Hash Generator produces UUID v4 identifiers and computes MD5, SHA-1, SHA-256, and SHA-512 hashes using the browser's native crypto.subtle API. The Password Generator uses cryptographically secure randomness via crypto.getRandomValues.
Privacy-first approach
Encoding and decoding tools handle some of the most sensitive data developers work with: authentication tokens, API keys, password hashes, and user data. Every tool on this page processes data entirely in your browser. Nothing is ever transmitted to a server, making these tools safe for production credentials and sensitive payloads.