Free online developer tools
Fast developer tools in one clean shelf.
Syntaxshel gives developers practical formatters, converters, generators, and decoders. Every tool runs locally in the browser and gets its own clean URL for search traffic.
Tool directory
Choose a developer utility
JSON & Data
Format, validate, and convert structured data quickly.
JSON Formatter & Validator
Format, validate, beautify, and minify JSON in your browser with clear error messages and copy-ready output.
HighJSON to CSV Converter
Convert arrays of JSON objects into clean CSV that can be opened in Excel, Google Sheets, or databases.
HighCSV to JSON Converter
Convert CSV rows into pretty JSON with automatic header detection and proper quoted field handling.
MediumYAML to JSON Converter
Convert simple YAML to JSON or JSON to YAML directly in the browser for config files and API payloads.
MediumXML Formatter
Format and validate XML documents with indentation, readable nesting, and parser error reporting.
Encode / Decode
Decode tokens, encode text, and generate hashes locally.
Base64 Encoder & Decoder
Encode text to Base64 or decode Base64 back to plain text, with Unicode-safe browser-only processing.
HighURL Encoder & Decoder
Encode URLs, decode percent-encoded strings, and clean query fragments without sending data to a server.
HighJWT Decoder
Decode JWT headers and payloads locally, inspect claims, and check token expiration details instantly.
MediumMD5 / SHA Hash Generator
Generate MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes from text in the browser.
MediumHTML Entity Encoder & Decoder
Escape HTML entities for safe display or decode entities back into readable text.
Code Formatters
Clean, compress, compare, and reshape source code.
JavaScript Minifier
Minify JavaScript snippets for quick sharing, testing, and lightweight production cleanup.
HighCSS Minifier
Compress CSS by removing comments, extra whitespace, and unnecessary separators.
MediumHTML Formatter
Beautify HTML markup into readable, indented code for debugging and publishing.
HighSQL Formatter
Format SQL queries with readable line breaks, uppercase keywords, and indentation.
MediumCode Diff Checker
Compare two snippets line by line and highlight additions, removals, and unchanged lines.
Generators
Generate IDs, passwords, regex matches, cron strings, and filler copy.
UUID / GUID Generator
Generate cryptographically strong UUID v4 values in batches and copy them instantly.
HighPassword Generator
Generate strong random passwords with adjustable length, symbols, numbers, and readable options.
HighLorem Ipsum Generator
Generate paragraphs, sentences, or words of clean placeholder copy for layouts and prototypes.
MediumCron Expression Builder
Build common cron expressions with simple controls and a plain-English schedule summary.
HighRegex Tester
Test regular expressions against sample text, inspect matches, and try flags safely in the browser.
Converters
Convert dates, colors, numbers, images, and markdown.
Unix Timestamp Converter
Convert Unix timestamps to local dates, UTC dates, ISO strings, and convert dates back to timestamps.
HighHEX / RGB Color Converter
Convert HEX, RGB, and HSL color values with a live swatch and copy-ready CSS output.
MediumBinary / Hex / Decimal Converter
Convert integers between binary, hexadecimal, decimal, and octal formats using BigInt precision.
MediumImage to Base64 Converter
Convert PNG, JPG, GIF, WebP, and SVG files into Base64 data URLs entirely in your browser.
MediumMarkdown Previewer
Preview Markdown as HTML with support for headings, lists, links, code blocks, and inline formatting.