Developer Tools
JSON, JWT, Base64, regex, and more — all free and private.
JSON Formatter & Validator
Format, validate, and beautify JSON data with syntax highlighting and error detection.
JWT Decoder
Decode and inspect JWT tokens. View header, payload, and verify signatures.
Base64 Encode/Decode
Encode text to Base64 or decode Base64 back to text. Supports UTF-8 and binary data.
URL Encode/Decode
Encode or decode URL components. Handle special characters, query strings, and full URLs.
Regex Tester
Test regular expressions with real-time matching, capturing groups, and explanation.
UUID Generator
Generate UUID v4 identifiers. Create single or bulk UUIDs with one click.
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from text or files using Web Crypto API.
CSS Minifier & Beautifier
Minify or beautify CSS code instantly. Remove comments and whitespace to reduce file size.
JavaScript Minifier
Minify JavaScript code by removing comments and whitespace. Reduce file size for faster page loads.
HTML Minifier
Minify HTML code by removing comments and collapsing whitespace. Preserve content in pre, code, and script tags.
Markdown to HTML Converter
Convert Markdown to HTML with live preview. Supports headers, bold, italic, links, code blocks, lists, and more.
Cron Expression Parser
Parse cron expressions to human-readable descriptions. See next scheduled run times and use common presets.
Crontab Generator
Build cron expressions visually with dropdowns and presets. Get a human-readable description and preview the next 5 run times.
Color Contrast Checker
Check WCAG 2.1 color contrast ratios for text and backgrounds. Verify AA and AAA compliance for normal and large text.
CORS Checker
Test Cross-Origin Resource Sharing (CORS) headers for any URL. Check if an API or resource allows requests from your domain.
DNS Lookup Tool
All-in-one DNS record inspector (A, AAAA, MX, TXT, NS, CNAME, CAA, SOA) using Cloudflare DNS-over-HTTPS. Checks DNSSEC status and CAA certificate authority authorization.
HTTP Cache Checker
Analyzes Cache-Control directives, ETag, Last-Modified, Vary, and CDN cache status headers. Explains each directive and grades caching strategy A-F.
HTML Validator
Free HTML5 validator: checks DOCTYPE, lang attribute, title, meta charset, missing alt attributes, duplicate IDs, deprecated elements (<center>, <font>, <marquee>), unlabeled inputs. W3C Validator alternative.
PWA Manifest Checker
Validates your Progressive Web App manifest.json for Chrome installability: name, icons (192×192 + 512×512), display mode, start_url, maskable icons, theme_color, screenshots. Installability grade A-F.
DNS Propagation Checker
Check DNS propagation status across 8 global resolvers (Cloudflare, Google, Quad9, OpenDNS, and more). Supports A, AAAA, CNAME, MX, TXT, NS records. Shows propagation percentage and consensus value.
.htaccess Generator
Generate Apache .htaccess rules for common configurations: force HTTPS, non-www redirect, block IPs, enable gzip compression, set cache headers, configure CORS, add security headers, and password protect directories.
SQL Formatter
Format and beautify SQL queries with proper indentation, keyword capitalization, and clause separation. Supports SELECT, INSERT, UPDATE, DELETE, CREATE TABLE, and JOINs. Works with MySQL, PostgreSQL, and SQLite syntax.
User Agent Parser
Parse any User-Agent string to identify browser name/version, operating system, device type (desktop/mobile/tablet), and bot detection. Supports Chrome, Firefox, Safari, Edge, and all major crawlers.
HTTP Status Code Lookup
Look up any HTTP status code (1xx–5xx) to see its official name, meaning, common causes, and how to fix it. Covers all 60+ standard status codes with practical explanations for developers.
CIDR Calculator
Calculate IP network details from CIDR notation: network address, broadcast address, first/last usable host, subnet mask, wildcard mask, and total host count. Supports IPv4 CIDR ranges from /0 to /32.
cURL to Fetch Converter
Convert cURL commands to JavaScript fetch() API code. Parses curl flags: -X (method), -H (headers), -d/--data (body), --json, -u (basic auth), --data-urlencode, -G (GET with data), and more.
Web Archive Checker
Check if a URL has been archived in the Wayback Machine (Internet Archive). Shows the most recent snapshot date, total snapshot count, and links to archived versions. Useful for checking deleted pages and historical content.
Email Address Validator
Validate an email address: checks RFC 5322 syntax, verifies the domain has MX records (can receive email), and detects disposable/temporary email providers. No email is sent — DNS lookup only.
ASN Lookup
Look up the Autonomous System Number (ASN), organization, country, and IP prefix for any IP address or domain. Uses Cymru DNS-based IP-to-ASN service for real-time lookups.
HTTP Compression Checker
Check if your web server supports gzip and Brotli compression. Compares compressed vs uncompressed response sizes, calculates compression ratio, checks Content-Encoding headers, and verifies Vary headers for correct CDN caching.
IPv6 Readiness Checker
Check if your domain is IPv6-ready. Tests AAAA records for www, root domain, mail server, and nameservers. Detects IPv6 PTR records, Teredo/6to4 tunnels, and dual-stack configuration. Get an IPv6 adoption score.
URL Parser & Inspector
Parse any URL into its components: protocol, hostname, port, pathname, query string parameters, and fragment. Decode URL-encoded values, inspect query parameters in a table, and get the normalized form of the URL.
JSON Schema Validator
Validate JSON data against a JSON Schema. Supports draft-07 with type, required, properties, enum, pattern, and more.
IP Geolocation
Look up the geographic location, ISP, and ASN for any IP address or domain. Shows country, region, city, and coordinates.
CSS Formatter
Format and prettify CSS code. Expands minified CSS, fixes indentation, normalizes whitespace, and sorts properties optionally.
chmod Calculator
Convert between Unix file permission notations — octal (755), symbolic (rwxr-xr-x), and binary. Toggle permissions and preview the chmod command.
Markdown Editor
Write and preview Markdown in real time. Side-by-side editor and live HTML preview with a formatting toolbar, word count, and HTML copy.
Markdown Table Generator
Create Markdown tables visually. Add rows and columns, set alignment, and copy the formatted GFM pipe table syntax.
Pixel to REM Converter
Convert between px and rem/em. Set your root font size, get an instant conversion table for all common sizes.
JSON to TypeScript
Convert a JSON object to TypeScript interfaces. Handles nested objects, arrays, optional properties, and union types.
String Escape / Unescape
Escape or unescape strings for JSON, HTML, URL, JavaScript, SQL, and RegExp. Supports encode and decode in both directions.
.gitignore Generator
Generate .gitignore files for any language or framework. Select Node.js, Python, Go, Java, macOS, Windows, VS Code, and more.
MIME Type Lookup
Look up MIME content types by file extension or find extensions by MIME type. Covers 200+ common media types.
curl Command Builder
Build curl commands visually. Set method, URL, headers, body, auth, and options — copy the ready-to-run curl command.
Semver Calculator
Semantic versioning calculator — bump versions, parse semver strings, and check if a version satisfies a version range.
Aspect Ratio Calculator
Calculate image and video aspect ratios. Enter any two values to find the third, or pick a preset ratio for common video and social media sizes.
Time Zone Converter
Convert times between any two time zones instantly. Compare world clocks, find overlapping working hours, and copy formatted timestamps.
CSS Specificity Calculator
Calculate the specificity of any CSS selector. Compare two selectors, understand which rule wins, and learn the specificity scoring system.
JSON Diff
Compare two JSON objects side by side. Highlights added, removed, and changed keys with a clear visual diff.
YAML Validator
Validate and format YAML syntax. Checks for parse errors, shows line numbers, and optionally converts to JSON for inspection.
HTML Entity Reference
Look up HTML entities by name, symbol, or decimal code. Find &, <, >, ©, ™, mathematical symbols, currency, and more.
Nginx Config Generator
Generate Nginx server configurations. Reverse proxy, SSL/TLS, redirects, caching, gzip, security headers, and rate limiting presets.
QR Code Scanner
Scan QR codes from uploaded images. Decode URLs, text, Wi-Fi credentials, vCards, and more. Works offline — no camera or server needed.
JSON to YAML Converter
Convert JSON to YAML format instantly. Supports nested objects, arrays, multiline strings, and comments. Handles large files with syntax validation.
HTML Entity Encoder/Decoder
Encode and decode HTML entities. Convert special characters to HTML entities and back. Supports named and numeric entities for XSS prevention.
Diff Checker
Compare two blocks of text side by side and see the differences highlighted. LCS-based diff algorithm with line-by-line comparison.
HTTP Status Code Checker
Complete HTTP status code reference with search and filtering. Browse all status codes (1xx-5xx) with descriptions, causes, and examples.
ASCII Table
Complete ASCII code reference table with all 128 characters. Search by decimal, hex, or character. Includes control characters, printable characters, and descriptions.
JavaScript Minifier
Minify JavaScript code by removing comments, whitespace, and newlines. See size savings with before/after comparison.
Regex Cheatsheet
Interactive regex reference with searchable syntax guide. Test patterns with live matching. Covers character classes, quantifiers, groups, and flags.
YAML Validator
Validate YAML syntax and convert to JSON. Checks indentation, duplicate keys, unclosed quotes, and common errors. Line-by-line error reporting.
XML Validator
Validate XML syntax and format it with pretty-printing. Uses DOMParser for accurate validation with line-by-line error reporting.
Unix Permissions Calculator
Calculate and convert Unix file permissions between symbolic (rwx) and octal (chmod) notation with an interactive checkbox grid.
JSON Schema Generator
Generate JSON Schema definitions from sample JSON data with automatic type inference, required field detection, and Draft 2020-12 support.
SVG Path Editor
Visualize and inspect SVG path data. Parse d attribute commands (M, L, C, Q, A, Z), configure viewBox, stroke, and fill — all in the browser.
DNS Record Reference
Comprehensive DNS record type reference. Look up A, AAAA, CNAME, MX, TXT, NS, SOA, SRV, CAA, and more with examples and RFC links.
HTTP Cookie Parser
Parse HTTP Set-Cookie header strings into structured fields: name, value, domain, path, expiry, Secure, HttpOnly, and SameSite attributes.
Luhn Algorithm Checker
Validate credit card numbers, IMEI codes, and other identifiers using the Luhn (mod 10) algorithm. Identifies card type and checks digit validity.
cURL to Code
Convert cURL commands into Python requests, JavaScript fetch, Node.js axios, Go net/http, and PHP code snippets. Parses headers, method, body, and auth.
JSON Key Sorter
Sort JSON object keys alphabetically, reverse alphabetically, or by key length. Recursively sorts nested objects and produces clean, formatted output.
Cron Next Run Calculator
Calculate the next N scheduled execution times for any cron expression. Supports 5 and 6 field formats including seconds, minutes, hours, day, month, and weekday.
HEX ↔ RGB Color Converter
Convert colors between HEX, RGB, HSL, and HSV formats instantly. Includes color picker and common web colors reference.
Matrix Calculator
Perform matrix operations: addition, subtraction, multiplication, transpose, and determinant. Supports 2×2 to 4×4 matrices with step-by-step results.
Quadratic Equation Solver
Solve quadratic equations ax² + bx + c = 0 using the quadratic formula. Shows real and complex roots, discriminant, vertex, and step-by-step solution.
Prime Factorization Calculator
Find the prime factorization of any integer. Check if a number is prime, list all prime factors, and compute factor trees. Also shows divisors and totient.
JSON Flatten / Unflatten
Flatten nested JSON objects into dot-notation keys (e.g., user.address.city) and unflatten them back. Configurable separator and array handling.
PPI Calculator
Calculate pixels per inch (PPI/DPI) for any screen. Enter resolution and diagonal size to find pixel density, compare against common displays, and check retina display thresholds.
JSONL / JSON Lines Formatter
Validate and format JSONL (JSON Lines / NDJSON) files where each line is a JSON object. Useful for machine learning datasets, log files, and streaming data.
Keyboard Event Tester
Press any key to see its JavaScript event properties: keyCode, key, code, charCode, and modifier states. Essential for debugging keyboard shortcut handlers.
IPv4 to Integer Converter
Convert IPv4 addresses to their 32-bit integer representation and back. Useful for database storage, IP range comparisons, and network programming.
.env File Parser
Parse and validate .env file contents. View key-value pairs in a table, detect common issues (spaces around =, unquoted values with special chars, duplicates), and convert to JSON.
Bitwise Calculator
Perform bitwise AND, OR, XOR, NOT, and shift operations on integers. View results in binary, hexadecimal, and decimal formats side by side.
JSON to XML Converter
Convert JSON to XML and XML to JSON online. Configurable root element name, attribute handling, and pretty-print indentation.
XML Formatter & Validator
Format, beautify, and validate XML documents. Pretty-print with customizable indentation, minify XML, and highlight syntax errors with line numbers.
String Hash Generator
Generate cryptographic hash digests from text using MD5, SHA-1, SHA-256, SHA-384, and SHA-512. Compare hashes and verify data integrity.
Unicode Character Lookup
Search and explore Unicode characters by name, codepoint, or category. Find emoji, symbols, and special characters with their HTML entities and CSS escape codes.
Epoch Time Converter
Convert Unix timestamps to human-readable dates and vice versa. Supports seconds, milliseconds, and microseconds with multiple timezone displays.
JSONPath Tester
Test JSONPath expressions against JSON data. Explore, filter, and extract values from nested JSON structures with real-time results.
Semver Comparator
Compare semantic version numbers. Parse and sort semver strings, check if a version satisfies a range, and understand major/minor/patch differences.
HTML Encoder / Decoder
Encode special characters to HTML entities (&, <, >, ") and decode HTML entities back to plain text. Useful for embedding HTML in code and preventing XSS.
PX to REM Converter
Convert CSS pixel values to REM (root em) units and vice versa. Supports custom base font size, batch conversion, and Tailwind CSS class lookup.
JSON Minifier
Minify JSON by removing all unnecessary whitespace and formatting. Also provides pretty-print with configurable indent. Shows space savings percentage.
IP Subnet Calculator
Calculate network address, broadcast address, subnet mask, host range, and usable host count from any IPv4 CIDR notation like 192.168.1.0/24.
DNS Record Generator
Generate DNS record syntax for A, AAAA, CNAME, MX, TXT, SPF, DKIM, DMARC, CAA, and SRV records in RFC and common panel formats.