Encoding Tools
Encoding & Hashing Tools
Base64, URL encoding, SHA hashing, UUID generation, and timestamp conversion. All run in your browser — your data never leaves your machine.
Decode base64 strings to text or JSON, or encode any text to base64. Handles URL-safe base64 and JWT payloads.
Percent-encode URLs and query parameters. Supports encodeURIComponent for parameter values and encodeURI for full URLs.
Generate SHA-1, SHA-256, SHA-384, or SHA-512 hashes from any text. Uses the browser's Web Crypto API — nothing is uploaded.
Generate UUID v4 identifiers using cryptographically secure randomness. Single UUID or bulk up to 1,000.
Convert Unix epoch timestamps to UTC, ISO 8601, and local time. Or convert any date string to a Unix timestamp.
Encode HTML special characters to named entities (& < >) or decode entities back to text. Handles decimal and hex numeric entities too.
Convert colors between HEX, RGB, and HSL formats. Visual color picker with component sliders and swatch palette.
Generate QR codes for URLs, WiFi credentials, vCards, and text. Custom size, error correction, and colors. Download PNG.
Decode and inspect JWT tokens. View header, payload claims, and expiry status. Timestamps auto-converted to human dates. Color-coded parts.
Encode any image to a base64 data URI for inline CSS or HTML. Or decode a data URI back to a viewable image. Shows size overhead.
Inspect any character's Unicode codepoint, UTF-8 bytes, UTF-16 words, HTML entities, JavaScript escape, CSS escape, and URL encoding.
Concepts
Why browser-based encoding?
Encoding and decoding runs entirely in your browser using native JavaScript APIs (atob/btoa, encodeURIComponent, Web Crypto). Nothing is sent to a server. This matters for JWT payloads that contain user data, API keys embedded in base64 strings, and other sensitive content.
Base64 vs URL encoding — not the same thing
Base64 represents binary data as ASCII text using a 64-character alphabet. URL encoding (percent encoding) replaces unsafe URL characters with %XX hex sequences. They solve different problems: base64 encodes arbitrary bytes for text transmission; URL encoding makes text safe for URLs.
SHA hashes are one-way
SHA-256 and SHA-512 are cryptographic hash functions — you can compute a hash from data but cannot reverse it. Use them for file integrity checks, HMAC signatures, and content addressing. They are not encryption — don't use a hash function alone to 'protect' data.