Base64 / URL / JWT / Regex / UUID / HTML Entity Toolkit

Encoding toolkit: Unicode-safe Base64 encoder/decoder, URL encoder/decoder, JWT decoder (with HS256 signature verification), regex tester (with flags support), UUID v4 / NanoID / ULID generator, HTML Entity encoder/decoder.

Base64 Encode/Decode

Online Base64 encoder and decoder with full Unicode support (Chinese, Emoji, multi-byte characters). All processing runs locally in your browser. No data sent to servers.

URL Encode/Decode

Online URL encoder and decoder tool. Supports URI component encoding (encodeURIComponent) and full URL encoding. Processed locally in your browser.

JWT Decoder

Online JWT (JSON Web Token) decoder with HS256 signature verification. View Header, Payload, and Signature segments. Decoded locally in your browser, token never sent to server.

Regex Tester

Online regex tester with support for g/i/m/s flags. Real-time match highlighting. Runs locally in your browser for fast regex debugging.

UUID Generator

Online unique ID generator: UUID v4 (RFC 4122), NanoID (URL-safe), ULID (sortable). Powered by crypto.getRandomValues. Generated locally in your browser.

HTML Entity Encoder

Online HTML entity encoder and decoder. Convert <, >, &, " and other special characters to HTML entities, or decode them back. Processed locally in your browser.

CSV JSON Converter

Online CSV and JSON converter: auto-detects headers, type inference. Convert CSV to JSON array, JSON to CSV table. Essential for data cleaning and API development.

Image to Base64

Online image to Base64 converter: drag & drop, paste, or upload an image to get a Base64 Data URI. Perfect for inline images and CSS.