# Kordu Tools > Kordu Tools (kordu.tools) is a free collection of 43+ browser-based online utilities. All tools process data client-side — files and data never leave the user's device. No signup required. Built by KORDU LTD, London, UK. ## What Users Can Do - Convert images between formats (PNG, JPG, WebP) instantly in the browser - Compress, resize, and crop images with social media presets - Strip EXIF metadata and GPS data from photos for privacy - Format, beautify, and minify JSON with sample data - Generate secure passwords and passphrases with crack time estimates - Check if passwords appear in known data breaches (via Have I Been Pwned k-anonymity) - Look up DNS, MX, SPF, SSL, and WHOIS records for any domain - Check your public IP address, ISP, and detect WebRTC leaks - Calculate mortgages, loans, BMI, percentages, compound interest, and tips - Convert timezones, calculate date differences, and track exact age - Generate QR codes, UUIDs, hashes, regex tests, and lorem ipsum text - Check WCAG colour contrast ratios for accessibility compliance ## Image Tools - [PNG to JPG Converter](https://kordu.tools/tools/image/png-to-jpg): Convert PNG to JPG. Adjustable quality. No upload — runs in browser via Canvas API. - [JPG to PNG Converter](https://kordu.tools/tools/image/jpg-to-png): Convert JPG to lossless PNG format. - [WebP Converter](https://kordu.tools/tools/image/webp-converter): Convert WebP to PNG or JPG with quality control. - [Image Compressor](https://kordu.tools/tools/image/image-compressor): Reduce image file size. Supports PNG, JPG, WebP output. - [Image Resizer](https://kordu.tools/tools/image/image-resizer): Resize to custom dimensions. Social media presets included. - [Image Cropper](https://kordu.tools/tools/image/image-cropper): Visual crop with aspect ratio presets (1:1, 4:3, 16:9, 9:16) and social media sizes (Instagram, Facebook, Twitter, YouTube, LinkedIn). - [EXIF Remover](https://kordu.tools/tools/image/exif-remover): Strip all metadata (EXIF, IPTC, XMP, GPS coordinates) from images. Shows exactly what data was found and removed. ## Developer Tools - [JSON Formatter](https://kordu.tools/tools/developer/json-formatter): Format, beautify, minify JSON. Configurable indent (2/4/tab). Includes 5 sample datasets for testing. - [Base64 Encoder/Decoder](https://kordu.tools/tools/developer/base64-encoder): Encode/decode Base64 with full UTF-8 support. - [UUID Generator](https://kordu.tools/tools/developer/uuid-generator): Generate v4 (random) and v7 (time-ordered) UUIDs. Up to 10,000 at once. - [Hash Generator](https://kordu.tools/tools/developer/hash-generator): MD5, SHA-1, SHA-256, SHA-512 hashes for text or files. - [Regex Tester](https://kordu.tools/tools/developer/regex-tester): Live regex testing with match highlighting, capture groups, and replace mode. - [Cron Expression Generator](https://kordu.tools/tools/developer/cron-generator): Visual cron builder with human-readable output and next 5 execution times. - [Timestamp Converter](https://kordu.tools/tools/developer/timestamp-converter): Convert Unix timestamps to human-readable dates and vice versa. - [HTTP Status Code Reference](https://kordu.tools/tools/developer/http-status-codes): Searchable reference for all HTTP status codes (1xx-5xx). ## Network & IP Tools - [What Is My IP](https://kordu.tools/tools/network/what-is-my-ip): Shows public IPv4/IPv6, ISP, city, country, timezone. - [DNS Lookup](https://kordu.tools/tools/network/dns-lookup): Query A, AAAA, MX, NS, TXT, CNAME, SOA, CAA records via Cloudflare DNS-over-HTTPS. - [MX Lookup](https://kordu.tools/tools/network/mx-lookup): Mail server records sorted by priority. Identifies provider (Google, Microsoft, etc.). - [SPF Record Checker](https://kordu.tools/tools/network/spf-checker): Validate SPF records. Warns about +all, multiple records, lookup limits. - [SSL Certificate Checker](https://kordu.tools/tools/network/ssl-checker): Certificate issuer, expiry, SANs, signature algorithm via Certificate Transparency logs. - [WHOIS Lookup](https://kordu.tools/tools/network/whois-lookup): Domain registration, registrar, expiry, nameservers via RDAP. - [WebRTC Leak Checker](https://kordu.tools/tools/network/webrtc-leak-checker): Detects if WebRTC exposes your real IP behind a VPN. - [Subnet Calculator](https://kordu.tools/tools/network/subnet-calculator): Network address, broadcast, usable hosts, wildcard mask from CIDR. - [MAC Address Generator](https://kordu.tools/tools/network/mac-address-generator): Random MAC addresses in colon/dash/dot formats. ## Security & Privacy Tools - [Password Generator](https://kordu.tools/tools/security/password-generator): Password and passphrase modes. Min digits/symbols, exclude ambiguous, crack time estimate. Rejection sampling for unbiased generation. - [Password Breach Checker](https://kordu.tools/tools/security/password-breach-checker): Check passwords against Have I Been Pwned. Uses k-anonymity — only 5 chars of a SHA-1 hash prefix are sent. Password never leaves the browser. ## Colour Tools - [Colour Picker](https://kordu.tools/tools/color/colour-picker): Pick colours, convert between HEX, RGB, HSL. - [Colour Contrast Checker](https://kordu.tools/tools/color/contrast-checker): WCAG 2.1 AA/AAA contrast ratio checker with live text preview at multiple sizes. ## Math & Number Tools - [Percentage Calculator](https://kordu.tools/tools/math/percentage-calculator): Four modes — X% of Y, X is what % of Y, X% more/less, percentage change. ## Finance Tools - [Mortgage Calculator](https://kordu.tools/tools/finance/mortgage-calculator): Monthly payment, total interest, amortisation schedule. 15/20/25/30yr presets. - [Loan Calculator](https://kordu.tools/tools/finance/loan-calculator): Monthly payment with early repayment savings comparison. - [Compound Interest Calculator](https://kordu.tools/tools/finance/compound-interest-calculator): Future value with daily/monthly/quarterly/annual compounding. - [Tip Calculator](https://kordu.tools/tools/finance/tip-calculator): Tip amount, total, per-person split with quick presets. ## Calculator Tools - [BMI Calculator](https://kordu.tools/tools/calculators/bmi-calculator): Metric and imperial. Colour-coded categories with healthy weight range. ## Time & Date Tools - [Timezone Converter](https://kordu.tools/tools/time-date/timezone-converter): Convert between multiple timezones simultaneously. - [Date Difference Calculator](https://kordu.tools/tools/time-date/date-difference): Years/months/days, total days, weeks, hours, business days. - [Age Calculator](https://kordu.tools/tools/time-date/age-calculator): Exact age, zodiac signs, generation, heartbeats, milestones, fun facts. - [Countdown Timer](https://kordu.tools/tools/time-date/countdown-timer): Live countdown to any date. Presets for New Year and Christmas. - [Stopwatch](https://kordu.tools/tools/time-date/stopwatch): Lap times with split tracking. - [Pomodoro Timer](https://kordu.tools/tools/time-date/pomodoro-timer): Configurable work/break cycles with audio notifications. ## Text Tools - [Word Counter](https://kordu.tools/tools/text/word-counter): Words, characters, sentences, paragraphs, reading time, speaking time. - [Lorem Ipsum Generator](https://kordu.tools/tools/text/lorem-ipsum-generator): Paragraphs, sentences, or words with classic opening option. ## Data Tools - [QR Code Generator](https://kordu.tools/tools/data/qr-code-generator): Custom colours, sizes (256-1024px), error correction levels. Download as PNG. ## Optional - [All Tools](https://kordu.tools/tools): Browse all 43+ tools by category. - [Blog](https://kordu.tools/blog): Guides and tutorials. - [Privacy Policy](https://kordu.tools/privacy): How we handle data. - [Terms of Service](https://kordu.tools/terms-of-service): Usage terms.