Encoding & decoding tools

Encode text to Base64, decode JWTs, percent-encode URLs, escape HTML, convert binary and hex, generate QR codes, and work with MIME headers — all client-side on space4.dev.

Base64, Base64URL, and image encoders/decoders
URL encode, decode, parse, and query-string tools
JWT decode, generate, inspect, and expiry check
HTML, Unicode, UTF-8, binary, hex, and octal converters
QR code and barcode generator/reader

Encoding & Decoding

49 tools

Encode and decode Base64, URL, HTML, Unicode, JWT, binary, and more — entirely in your browser.

Base64

Base64 Encoder

Encode text to Base64 instantly in your browser.

Base64 Decoder

Decode Base64 strings back to readable text.

Base64 Image Decoder

Preview images from Base64 or Data URI strings.

Base64 Image Encoder

Convert images to Base64 for embedding in CSS or HTML.

Base64 URL Encoder

Encode text as URL-safe Base64 (Base64URL).

Base64 URL Decoder

Decode URL-safe Base64 (Base64URL) strings.

URL

URL Encoder

Percent-encode text for safe use in URLs.

URL Decoder

Decode percent-encoded URL strings.

URL Parser

Break a URL into protocol, host, path, query, and hash.

URL Query Parser

Parse query strings into a readable JSON object.

URL Builder

Build a full URL from JSON parts.

URL Query String Generator

Turn a JSON object into a query string.

HTML

HTML Encoder

Encode special characters for safe HTML output.

HTML Decoder

Decode HTML entities back to plain text.

HTML Escape

Escape HTML to prevent XSS in text contexts.

HTML Unescape

Unescape HTML entities to original characters.

Unicode

Unicode Encoder

Convert text to Unicode escape sequences.

Unicode Decoder

Decode \uXXXX and \u{…} escape sequences.

Unicode Escape

Escape text as Unicode code-point sequences.

Unicode Unescape

Unescape Unicode sequences to readable text.

ASCII ↔ Unicode Converter

Convert between plain text and Unicode escapes.

JWT

JWT Decoder

Decode JWT header and payload without a server.

JWT Generator

Generate HS256 JWTs locally with Web Crypto.

JWT Inspector

Inspect JWT claims in a readable JSON view.

JWT Expiry Checker

Check iat, nbf, and exp claims on a JWT.

Text Encoding

UTF-8 Encoder

Encode text to UTF-8 byte values.

UTF-8 Decoder

Decode UTF-8 byte lists back to text.

UTF-16 Converter

Convert text to and from UTF-16 code units.

ASCII Converter

Convert text to ASCII / Unicode code points.

Binary Converter

Convert text to binary and back.

Hex Converter

Convert text to hexadecimal and back.

Octal Converter

Convert text to octal byte values and back.

Binary & Hex

Text → Binary

Convert plain text into binary bytes.

Binary → Text

Convert binary bytes back into text.

Text → Hex

Convert plain text into hexadecimal.

Hex → Text

Convert hexadecimal into text.

Binary ↔ Hex

Convert between binary and hexadecimal.

Decimal ↔ Binary

Convert decimal numbers to binary and back.

Decimal ↔ Hex

Convert decimal numbers to hex and back.

Data URI

Data URI Generator

Build data: URIs from MIME type and content.

Data URI Decoder

Decode data: URIs back to MIME + payload.

Image → Data URI

Upload an image and get a ready-to-use Data URI.

MIME

MIME Type Lookup

Look up MIME types from file extensions.

MIME Header Decoder

Decode RFC 2047 encoded-word email headers.

MIME Header Encoder

Encode text as RFC 2047 UTF-8 Base64 headers.

QR & Barcode

QR Code Generator

Generate QR codes from text or URLs locally.

QR Code Decoder

Decode QR codes from uploaded images.

Barcode Generator

Generate CODE128, EAN13, UPC, and more barcodes.

Barcode Reader

Capture or paste barcode values for quick notes.

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