Free Online Tools for Developers & SysAdmins

IP Address Checker Find your public IP address and details. DNS Lookup Query DNS records for any domain. Port Checker Check whether a port is open on a host. Subnet Calculator Calculate subnets and CIDR ranges. Password Generator Create strong random passwords. UUID Generator Generate UUID v1, v3, v4, v5 and NIL identifiers online. Base64 Encoder Encode and decode Base64. JSON Formatter Format and validate JSON. Cron Generator Build cron expressions easily. chmod Calculator Calculate Linux file permissions. Timestamp Converter Convert between Unix timestamps and dates. HTML Encoder & Decoder Encode and decode HTML entities and special characters. URL Encoder / Decoder Encode and decode URLs and text using URL encoding. JWT Parser Decode JWT tokens and inspect headers, payloads, claims, and expiration dates. Hash Generator Generate text hashes using SHA-1, SHA-256, SHA-384, and SHA-512 algorithms. Regex Tester Test regular expressions and explore matches and capture groups. URL Parser Parse URLs and extract protocol, hostname, path, port, and query parameters. JSON Minifier Minify JSON and reduce its size by removing unnecessary whitespace. JSON Diff Checker Compare two JSON files and find added, removed, or modified values. JSON Viewer View JSON in an interactive tree, expand nodes, sort keys, and format data. YAML to JSON Converter Convert YAML to formatted JSON instantly with validation and customizable indentation. JSON to YAML Converter Convert JSON to YAML instantly with validation and customizable indentation. YAML Viewer & Formatter View, format, and validate YAML with an interactive tree and customizable indentation. YAML to TOML Converter Convert YAML to TOML online instantly with syntax validation. TOML to YAML Converter Convert TOML to YAML online with syntax validation and formatting options. JSON to TOML Converter Convert JSON to TOML online with syntax validation and instant results. TOML to JSON Converter Convert TOML to formatted JSON instantly with syntax validation. Base64 Encoder & Decoder Encode and decode Base64 text with Unicode and URL-safe support. Base64 File Converter Convert files to Base64 and decode Base64 into downloadable files. HTML Entities Encoder & Decoder Encode and decode HTML entities and special characters. Case Converter Convert text to uppercase, lowercase, camelCase, snake_case, and more. Text Statistics Count characters, words, lines, sentences, and text size instantly. Text Diff Compare two texts and highlight added, removed, and modified lines. Markdown to HTML Convert Markdown to HTML with live preview, code copying, and PDF printing. HTML to Markdown Convert HTML to Markdown with live conversion, code copying, and file download. XML Formatter Format, minify, and validate XML online with customizable indentation. XML to JSON Converter Convert XML to JSON with customizable indentation and instant results. JSON to XML Converter Convert JSON and JSON5 to XML with customizable indentation and instant results. JSON to CSV Converter Convert JSON and JSON5 arrays to CSV with customizable delimiters and instant results. CSV to JSON Converter Convert CSV data to formatted JSON with automatic delimiter detection and customizable options. Color Converter Convert colors between HEX, RGB, HSL, HWB, LCH, CMYK and color names. Basic Auth Generator Generate HTTP Basic Authorization headers from a username and password. Email Normalizer Normalize email addresses for easier comparison, deduplication, and data cleaning. ASCII Art Text Generator Create ASCII art text using a variety of fonts and styles. Text to Unicode Converter Convert text to Unicode decimal references and Unicode back to text. Outlook SafeLink Decoder Decode Microsoft Outlook SafeLinks and extract original destination URLs. JavaScript Regex Cheatsheet Quick reference for JavaScript regular expressions, syntax, quantifiers, groups, and matching patterns. PDF Signature Checker Inspect digital signatures and certificate details in PDF files directly in your browser. Numeronym Generator Convert long words into short numeronyms like i18n, l10n, and a11y. MAC Address Generator Generate random MAC addresses with custom prefixes, separators, and letter case. Text to Binary Converter Convert text to binary and binary back to text instantly. IBAN Validator and Parser Validate IBAN numbers, check errors, and extract banking information. String Obfuscator Mask text and hide characters while keeping selected parts visible. Emoji Picker Search, browse, and copy emojis, Unicode escapes, and code points. Password Strength Analyser Analyse password strength, entropy, and estimated brute-force cracking time. Camera Recorder Record webcam videos and capture photos directly in your browser. List Converter Convert, sort, clean, and format text lists with customizable separators. Phone Parser and Formatter Validate, analyze, and format international phone numbers. IPv4 Range Expander Find the smallest CIDR network covering an IPv4 address range. HTTP Status Codes Explore HTTP status codes and their meanings with instant search. IPv6 ULA Generator Generate unique local IPv6 prefixes and /64 subnets using a MAC address. IPv4 Address Converter Convert IPv4 addresses to decimal, hexadecimal, binary, and IPv6 formats. Benchmark Builder Compare benchmark measurements using averages, variance, and relative performance. User Agent Parser Parse User-Agent strings to identify browser, operating system, device, rendering engine, and CPU architecture. Docker Run to Docker Compose Converter Convert Docker run commands into Docker Compose YAML. Docker Compose to Docker Run Converter Docker Compose Validator Validate Docker Compose YAML and detect common configuration errors. Bcrypt Hash Generator Generate and verify bcrypt password hashes securely in your browser. BIP39 Mnemonic Generator Generate and validate BIP39 mnemonic phrases from entropy in your browser. Chronometer Measure elapsed time with a precise stopwatch and lap timer. Slugify String Convert text into a URL-friendly slug. Lorem Ipsum Generator Generate placeholder text. Percentage Calculator Calculate percentages. Temperature Converter Convert Celsius, Fahrenheit and Kelvin. Roman Numeral Converter Convert Roman and decimal numbers. Integer Base Converter Convert binary, octal, decimal and hexadecimal integers. Random Port Generator Generate random port numbers. Token Generator Generate cryptographically secure random tokens. Keycode Info Inspect keyboard event properties. Meta Tag Generator Generate basic HTML SEO meta tags. Text to NATO Alphabet Convert letters to the NATO phonetic alphabet. SVG Placeholder Generator Create downloadable SVG placeholders. MIME Types Look up common file MIME types. SQL Formatter Format SQL statements for readability. OTP Generator and Validator Generate and verify TOTP codes locally. RSA Key Pair Generator Generate RSA-OAEP public and private keys locally. QR Code Generator Generate QR codes for text and URLs locally. WiFi QR Code Generator Generate WiFi connection QR codes locally. MAC Address Lookup Find MAC address manufacturers using the IEEE OUI registry. ULID Generator Generate unique, sortable ULIDs instantly. Math Evaluator Calculate mathematical expressions online. Date & Time Converter Convert dates and timestamps between ISO, RFC, Unix, Excel, and MongoDB formats. Device Information View your screen, browser, platform, and device information. Encryption / Decryption Encrypt and decrypt text using AES, TripleDES, Rabbit and RC4. ETA Calculator Calculate task duration and estimated completion time. Git Memo Quick Git command reference with search and copy. Crontab Generator Validate and explain Cron expressions with examples. HMAC Generator Generate HMAC hashes using a secret key and multiple algorithms. HTML WYSIWYG Editor Edit HTML visually, format source code and preview the result.