Dev Tools

Category overview

Developer tools cover small repeated checks during implementation and debugging, including JSON formatting, diffs, UUIDs, JWTs, regular expressions, colors, and CSS units. The public list prioritizes tools with clear inputs and outputs for quick verification before opening a console or script.

For tokens, keys, logs, or other sensitive values, follow your organization policy before pasting data into any browser-based tool. Browser-side processing does not replace data-handling rules.

Currently showing 66 reviewed tools, including JSON Formatter, UUID Generator, Password Generator, JWT Decoder, Regex Tester.

Dev Tools List

• JSON Formatter - Beautify or minify JSON strings instantly and check for validity errors.
• UUID Generator - Generate up to 20 cryptographically secure UUID v4 values at once.
• Password Generator - Generate secure random passwords in the browser by choosing length, character set, and count.
• JWT Decoder - Decode a JWT header and payload to view the JSON and key claims.
• Regex Tester - Enter a regex pattern to see matches in text in real time.
• QR Code Generator - Convert text or a URL into a QR code and download it as an image.
• Wi-Fi QR Code - Make a QR code from Wi-Fi network info so guests can connect easily.
• UTM Parameter Builder - Add UTM parameters to a URL to build a marketing campaign tracking link.
• CSS vw Unit Converter - Convert px to viewport-width vw units, or the reverse.
• CSS clamp() Generator - Auto-generate a CSS clamp() function from min/max values and a viewport range.
• Color Palette Picker - Pick a color and view its HEX, RGB, HSL values plus complementary and analogous colors.
• SQL Formatter - Neatly align SQL queries by keywords and clauses.
• HTML Formatter - Tidy HTML markup with consistent indentation and line breaks.
• CSS Formatter - Neatly align CSS code by rules and properties.
• JavaScript Formatter - Tidy JavaScript code for readability using Prettier rules.
• JS/CSS Minifier - Minify JavaScript and CSS code by removing whitespace and applying minify rules.
• XML Formatter - Parse an XML document and indent it by hierarchy.
• YAML Formatter - Tidy a YAML document with consistent indentation and line breaks.
• Code Diff Tool - Compare two code or text inputs line by line to show additions and deletions.
• Cron Expression Generator - Generate a cron expression by combining minute, hour, day, month, and weekday values.
• Cron Next Run Calculator - Calculate the next run times of a cron expression based on the current time.
• HTTP Status Code Lookup - Quickly look up the name and meaning of an HTTP status code.
• MIME Type Lookup - Quickly find file extensions and MIME types.
• Keyboard Event Inspector - Instantly check the key, code, and modifier values of a key press event.
• User-Agent Analyzer - Extract browser, OS, and device info from a User-Agent string.
• Regex Replace Tester - Apply a regex pattern and replacement value to see the result.
• JSONPath Tester - Extract values from JSON data using a JSONPath expression.
• CSS box-shadow Generator - Adjust shadow values with sliders and generate box-shadow CSS.
• CSS border-radius Generator - Check rounded-corner values with a preview and generate border-radius CSS.
• CSS gradient Generator - Adjust colors and angle to generate linear-gradient CSS.
• CSS easing Generator - Adjust cubic-bezier values to generate a CSS easing function.
• Flexbox Generator - Adjust flex-direction, justify-content, align-items, and gap to generate Flexbox CSS.
• Grid Generator - Adjust columns, gap, and item count to generate CSS Grid layout code.
• z-index Organizer - Enter names and z-index values per line and sort from lowest to highest.
• cURL → fetch Converter - Convert a cURL command into JavaScript fetch code.
• fetch → axios Converter - Convert fetch code into the axios request format.
• HTTP Header Parser - Parse a header string into key-value form.
• .env Sorter - Sort keys in a .env file and find duplicate keys.
• package.json Viewer - Neatly organize scripts, dependencies, and devDependencies.
• semver Comparator - Compare two semantic versions and interpret version range notation.
• Gitignore Generator - Generate gitignore templates by language/framework.
• Dockerfile Formatter - Tidy Dockerfile commands and present the structure clearly.
• Docker Compose Formatter - Neatly tidy docker-compose YAML.
• URL Parser - Break a URL into protocol, host, path, and query.
• User-Agent Generator - Generate User-Agent strings for testing.
• API Latency Summary - Calculate the mean, p95, and p99 of a list of response times.
• GraphQL Formatter - Tidy GraphQL queries and mutations.
• GraphQL Variable Merger - Merge a GraphQL query and variables JSON into an API request body.
• SQL IN Clause Generator - Convert a line list into a SQL IN (…) form.
• JSON Mock Data Generator - Generate a sample JSON array based on field definitions.
• CSS text-shadow Generator - Adjust X/Y offset, blur, color, and opacity to make CSS text-shadow code.
• CSS filter Generator - Generate CSS filter values like blur, brightness, contrast, and grayscale with a preview.
• Color Shades Palette Generator - Generate a 50–950 Tailwind-style shade palette from one base HEX color.
• Meta / OG Tag Generator - Generate title, description, canonical, OG, and Twitter Card meta tag HTML.
• JSON → Table Converter - Convert a JSON object array into a rows-and-columns table and export to CSV.
• JSON Tree Viewer - Show JSON data as a collapsible/expandable tree structure.
• CSS Specificity Calculator - Calculate and compare the specificity score of CSS selectors.
• Git Branch Name Generator - Convert a task title into a name following Git branch naming conventions.
• Hash Generator - Hash text with MD5, SHA-1, SHA-256, and SHA-512. Supports HEX and Base64 output.
• JSON Schema Validator - Validate JSON data against a JSON Schema (Draft-7) and show error locations as JSON Pointers.
• Browser Info - See the browser, OS, device, screen and locale details your browser reports — all locally.
• RSA Calculator - Derive an RSA key (n, φ, d) from two primes and a public exponent, and walk through encryption/decryption. For learning only.
• API Key Generator - Generate cryptographically secure random API keys in Base62, Hex, Base64URL or UUID formats, entirely in your browser.
• XML Validator - Check whether XML is well-formed, view error messages, and get a tidy indented version.
• YAML Validator - Validate YAML syntax, show error line/column positions, and preview the parsed JSON.
• Color Contrast Checker - Calculate the WCAG 2.1 contrast ratio between a foreground and background color and check AA / AAA accessibility compliance.