Free Online Developer Tools
25 toolsBoost your workflow with free online developer tools built for daily coding tasks. Validate and format JSON, generate cron expressions, decode JWT tokens, look up IP addresses, generate bulk UUIDs, and minify HTML, CSS, or JavaScript — all without leaving your browser.
Dev tools
25Regex Tester
Free online regex tester. Test JavaScript regular expressions with live match highlighting, group captures, and full flag support.
Regex Replace
Free regex find and replace. Apply regex substitutions with g, i, m, s flags, live match count, and instant preview results.
SQL Formatter
Free SQL formatter and beautifier. Format messy SQL queries with proper indentation and keyword casing for MySQL, PostgreSQL, and more.
Cron Job Generator
Free cron expression generator. Build and validate cron schedule strings visually. Supports standard 5-field and extended 6-field cron.
JSON Minifier
Free JSON minifier. Compress JSON by removing all whitespace and formatting. Reduce API response size and storage footprint instantly.
XML Formatter
Free XML formatter and beautifier. Pretty-print XML documents with proper indentation. Validates well-formedness before formatting.
CSS Minifier
Free CSS minifier. Strip whitespace, comments, and redundant properties from CSS stylesheets to reduce file size and improve load time.
HTML Minifier
Free HTML minifier. Remove whitespace and comments from HTML to reduce page size and improve web page load performance.
JS Minifier
Free JavaScript minifier. Compress JS by stripping whitespace and comments. Reduces bundle size for faster-loading web pages.
JavaScript Keycode Finder
Free JavaScript key code viewer. Press any key and instantly see its keyCode, key name, which property, and charCode value.
Smart URL Parser
Free URL parser. Decompose any URL into protocol, hostname, port, pathname, query parameters, and hash fragment components.
URL Query String Parser
Free URL query string parser and builder. Parse query strings into key-value pairs or build a query string from key-value input.
UUID Generator (v1–v8)
Free bulk UUID v4 generator. Generate any number of random UUIDs in one click. Copy all results or download as a plain text file.
JWT Decoder
Free JWT decoder. Decode and inspect JSON Web Token header and payload instantly. No signature validation, no private key needed.
camelCase Converter
Free camelCase converter. Convert text, snake_case, kebab-case, or PascalCase to camelCase for JavaScript variables and functions.
snake_case Converter
Free snake_case converter. Convert camelCase, PascalCase, or plain text to snake_case. Supports SCREAMING_SNAKE_CASE and batch input.
kebab-case Converter
Free kebab-case converter. Convert text or other case formats to kebab-case for CSS class names, URL slugs, and HTML attributes.
PascalCase Converter
Free PascalCase converter. Convert text, camelCase, or snake_case into PascalCase for TypeScript class names and React components.
JSON Validator
Free JSON validator and formatter. Check if JSON is valid and view a formatted, readable version with line numbers and error hints.
Unix Timestamp Converter
Free Unix timestamp converter. Convert between Unix epoch timestamps and human-readable dates. Supports seconds and milliseconds.
HTML Tag Remover
Free HTML tag stripper. Remove all HTML tags from text and extract only the plain text content. Useful for web scraping and cleanup.
Meta Tag Generator
Free HTML meta tag generator. Create SEO title, description, Open Graph, and Twitter Card tags for any web page in seconds.
URL Slug Generator
Free URL slug generator. Convert any title or phrase into a clean, lowercase, hyphenated slug for SEO-friendly URLs.
IPv6 Address Formatter
Free IPv6 address formatter. Expand, compress, and validate IPv6 addresses. Convert between full and abbreviated notation instantly.
IP Address Lookup
Free browser network info and local IP checker. Inspect browser-visible network details, private IP candidates, timezone, language, and platform.
Frequently Asked Questions
Can I use these tools in a corporate or restricted network?
Yes. All tools run entirely in the browser with no outbound API calls (except IP Lookup, which queries a public IP geolocation API). No data is sent to our servers.
Does the JWT decoder verify signatures?
The JWT Decoder Lite decodes and displays the header and payload but does not verify the signature. For signature verification you need the signing secret or public key, which should never be shared with a third-party website.
How do I generate a cron schedule?
Open the Cron Generator, select the frequency (every minute, hourly, daily, weekly, monthly, or custom), and the tool generates the correct cron expression with a human-readable description.