Convertter - Free Online Unit Converter & Browser Tools
Welcome to Convertter, a fast, free online unit converter and privacy-first suite of browser tools designed for everyday users, engineers, students, and developers. Unlike traditional cloud conversion websites that upload your personal documents, audio tracks, or data files to remote servers, every Convertter tool executes 100% locally inside your web browser using modern client-side JavaScript and WebAssembly.
Whether you need an accurate online unit converter for scientific and culinary measurements, a PDF and DOCX document converter, an in-browser audio and HEIC image converter, a global World Clock meeting planner with automatic Daylight Saving Time (DST) alerts, or synthetic test data and developer calculators, Convertter delivers instant results with zero file uploads and complete privacy.
High-Precision Online Unit Converter Categories
Our free online unit converter supports over 100 measurement units across 14 scientific, engineering, and household categories. Each unit converter applies verified conversion factors aligned with international NIST SI Measurement Standards and the BIPM International System of Units:
- Length Converter – Convert Meter (m), Kilometer (km), Centimeter (cm), Millimeter (mm), Foot (ft), Inch (in), and Mile (mi) with practical unit explanations.
- Weight & Mass Converter – Convert Kilogram (kg), Gram (g), Milligram (mg), Metric Ton (t), Pound (lb), Ounce (oz), and Carat (ct) with practical unit explanations.
- Temperature Converter – Convert Celsius (°C), Fahrenheit (°F), and Kelvin (K) with practical temperature scale explanations.
- Power Converter – Convert Watts (W), Kilowatts (kW), Megawatts (MW), Horsepower (hp), Foot-Pounds per Minute, and BTU per Hour (BTU/h) with practical unit explanations.
- Energy Converter – Convert Joule (J), Kilojoule (kJ), Calorie (cal), Kilocalorie (kcal), Watt-hour (Wh), and Kilowatt-hour (kWh) with practical unit explanations.
- Pressure Converter – Convert Pascal (Pa), Kilopascal (kPa), Bar (bar), PSI (psi), Atmosphere (atm), and Torr with practical unit explanations.
- Kitchen & Cooking Converter – Convert Gram (g), Milliliter (mL), Cup (cup), Tablespoon (tbsp), and Teaspoon (tsp) with ingredient density support and unit explanations.
- Nutrition Facts Hub – Browse official USDA nutritional values (calories, protein, carbs, fats, fiber) per 100g and calculate custom recipe and meal portions. (Nutritional Reference Table • Meal & Recipe Calculator)
- Area Converter & Volume Converter – Square Meter (m²), Hectare (ha), Acre (ac), Liter (L), Cubic Meter (m³), and Gallon (gal) with practical unit explanations.
- Speed Converter & Digital Storage Converter – km/h, mph, knots, Mach, bytes, megabytes, gigabytes, and terabytes.
Private In-Browser Media, PDF & Document Tools
Process sensitive documents, ebooks, spreadsheets, images, and audio recordings directly on your computer or phone without uploading files to the cloud:
- PDF & Document Suite – Convert PDF to Word (DOCX), merge and split PDF pages, and inspect document metadata in your browser.
- EPUB & Markdown Document Converter – Extract clean text from EPUB ebooks and render Markdown to formatted PDF documents.
- Audio Converter & MP4 Audio Extractor – Convert MP3, WAV, FLAC, M4A, AAC, OGG, and extract audio tracks from MP4 videos locally.
- Universal Image & HEIC Converter – Batch convert Apple HEIC, WebP, PNG, JPG, and SVG images with ZIP download.
- Spreadsheet Converter – Convert between CSV, Excel (XLSX), and JSON data tables locally.
Global Timezone Planner, Calculators & Developer Browser Tools
Coordinate international teams, run engineering calculations, and generate compliant synthetic test data with our specialized browser tools:
- World Clock Meeting Planner & DST Checker – Compare global cities and standard timezones (UTC, CET, IST, EST, PST, BRT, JST) with automatic Daylight Saving Time transition dates.
- Scientific & Standard Calculator Online – Full-featured arithmetic and scientific calculator with memory tape and keyboard shortcuts.
- IP Subnet & CIDR Calculator – Calculate IPv4 network ranges, broadcast addresses, wildcard masks, and usable host counts.
- Synthetic Test Data Generator – Generate realistic mock profiles, addresses, and checksum-valid national IDs (CPF, SSN, DNI, NIF, NINO, Steuer-ID) across 12 countries for QA testing.
- Developer Tools Hub & Cryptography Tools – JSON formatter, JWT decoder, Regex tester, Base64 encoder, UUID generator, SHA-256 hashing, and Bcrypt tools.
- Pomodoro Focus Timer – Customizable work and break intervals for deep productivity.