Free Developer Tools
Free online developer tools from ToolZone. JSON Formatter, Base64 Encoder / Decoder, URL Encoder / Decoder, HTML Encoder / Decoder and more. No signup. Every tool runs directly in your browser and is built for quick, repeat use.
10 Developer tools
Free JSON formatter, validator and minifier. Pretty-print JSON with proper indentation, catch syntax errors, or compress to a single line. Runs in your browser.
Developer Base64 Encoder / DecoderEncode text to Base64 or decode Base64 back to UTF-8 text. Free online Base64 tool, no signup, runs entirely in your browser.
Developer URL Encoder / DecoderEncode special characters in URLs (spaces, &, ?, =) to %xx escape sequences, or decode percent-encoded URLs back to readable text. Free, instant.
Developer HTML Encoder / DecoderEncode HTML entities (&, <, >, ", ') or decode them back to text. Free online HTML escape tool, instant and browser-based.
Developer Regex TesterTest JavaScript regular expressions live with match highlighting, flag support (g, i, m, s, u) and instant feedback. Free, no signup.
Developer Hash GeneratorGenerate cryptographic hashes (SHA-256, SHA-1, SHA-512) of any text instantly. Free online hash generator using the Web Crypto API.
Developer JSON to CSV ConverterConvert JSON arrays or objects into CSV for Excel, Google Sheets and data exports. Free JSON to CSV converter that runs in your browser.
Developer Timestamp ConverterConvert Unix timestamps (epoch seconds or milliseconds) to human-readable dates and back. Free online timestamp converter.
Developer JWT DecoderDecode a JWT online to read its header, payload claims and expiry status. Free JWT decoder that runs 100% in your browser — tokens are never uploaded.
Developer UUID GeneratorGenerate random UUID v4 (GUID) values in bulk — lowercase, uppercase, or without dashes. Free online UUID generator using the Web Crypto API.
Related guides
Learn when to escape HTML, which characters need entities, how encoding helps prevent XSS, and when decoding HTML entities is safe.
How to Convert JSON to CSVConvert JSON arrays and objects into CSV for spreadsheets, databases, and reports, including headers, nested values, and escaping rules.
URL Encoding Query ParametersLearn why URLs need percent encoding, which characters break query strings, and when to use encodeURIComponent instead of encodeURI.
How to Validate JSON and Fix Common Syntax ErrorsLearn how to validate JSON and fix the most common errors: trailing commas, single quotes, unquoted keys, comments and unescaped characters — with examples.
Base64 Is Not Encryption: What It Actually DoesBase64 is reversible encoding, not encryption. Learn what Base64 is for, when to use it, its 33% size cost, and safe alternatives for protecting data.
How to Decode a JWT SafelyLearn what is inside a JSON Web Token, how to decode the header and payload, how to read exp and iat claims, and why decoding is not verification.