Free Online Professional Tools Tools

Professional online CAD sheet cutting optimizer. Upload DXF files to generate optimal nesting layouts for engineering and manufacturing. Save material, improve efficiency—no install required.

Free online prism effect calculation tool supporting prism diopter and angle conversion, prism power calculation, prism deviation calculation, and binocular prism synthesis. Ideal for eyeglass dispensing, optical design, and optometric calculations.

Free online shipping mark generator with 4 templates: standard, simple, table, and vertical layouts. Easily fill in consignee, destination, package number, weight, origin and other export cargo information. Add special handling marks like fragile, keep dry, this side up. Export high-quality PNG images and PDF documents for direct printing on cargo packaging.

Free online typing practice tool with multiple difficulty levels and text types. Real-time statistics for WPM, accuracy, and error rate to help improve typing efficiency.

Free online screw quantity to weight conversion tool, supports multiple screw specifications (M2-M24) and materials (carbon steel, stainless steel, brass, aluminum). Quickly calculate total screw weight for procurement, warehousing, and logistics.

Free online CAD drawing preview tool supporting DWG, DXF, DWF formats. View engineering drawings directly in browser without AutoCAD installation. Features zoom, pan, layer control and more.

Free online book file preview tool supporting EPUB, PDF, DOCX, MOBI, TXT and other common e-book formats. No download required, read e-books directly in your browser with table of contents navigation, theme switching, font adjustment and more.

Free online office document preview tool supporting Word(doc/docx), Excel(xls/xlsx), PowerPoint(ppt/pptx), PDF and more formats. View documents directly in browser without installing Office software.

Free online Draw.io workflow diagram editor supporting flowcharts, mind maps, UML diagrams, network topology diagrams and more. Create and edit professional diagrams directly in your browser without installation, with support for multiple export formats.

Free online mind mapping tool supporting node CRUD, drag-and-drop layout, multiple themes, import and export. Create and edit mind maps directly in your browser without registration. Export to PNG, SVG, JSON formats.

Free online whiteboard and mindmap tool supporting freehand drawing, shape dragging, mind mapping and more. Create and edit whiteboard content directly in your browser without registration. Export to PNG and JSON formats.

Free online 3D model preview tool supporting OBJ, GLTF, GLB, FBX, STL, PLY and other 3D formats. View, rotate and zoom 3D models in browser without any software installation.

Free online PPT to lower version converter. Convert high-version PowerPoint files (.pptx) to compatible formats for 2007/2010 or 2013/2016, solving compatibility issues with older Office versions.

Free online formula editor supporting mathematical formula editing, calculation and visual preview. Supports variable definition, common math functions, formula templates and result export to image.

Free online sprite sheet splitter tool. Automatically split sprite sheets into individual sprites by columns and rows. Supports PNG, JPG, WebP formats. Preview split results and download all sprites as a ZIP package with one click.

Free online Tarot card divination tool. Supports 1-card, 3-card, and 5-card spreads with all 78 cards including upright and reversed interpretations. Get accurate guidance and spiritual advice.

Free online Braille converter tool. Supports bidirectional conversion between text and Braille (Grade 1 Braille). All processing happens in your browser - no file upload needed, privacy guaranteed.

Free online Parquet file viewer. Upload and preview Parquet format files. No server upload required, all operations are done locally in your browser to protect your data privacy.

Free online Apache ORC file viewer. Upload .orc files to view contents, schema, and metadata. Supports large file pagination, data search and filtering, CSV export, and more.

Free online Feather icon browser and retriever. Search, filter by category, and copy SVG code. Includes 287 beautifully simple open-source icons.

Free online HDF5 file viewer tool. Open and browse HDF5/HDF4 format files with tree structure navigation. View dataset contents, attributes, data types, and dimension information. All processing happens locally in your browser - no server upload needed, keeping your data secure.

Free online mortar and cement calculator. Supports masonry and plastering mortar. Automatically calculates mix ratios based on cement grade (32.5/42.5/52.5) and mortar strength grade (M5-M20) per JGJ/T 98-2010 standard.

Free online ETF DCA (Dollar-Cost Averaging) calculator. Simulate regular investment plans, calculate total invested, total return, annualized return rate, and other key metrics. Ideal for fund and ETF long-term investment planning.

Free online EV charging cost calculator. Calculate charging energy, charging time, and charging fees for home charging, public fast charging, and supercharging scenarios. Helps EV owners plan their charging budget.

Free online solar power generation estimator. Calculate daily, monthly, and yearly energy output and carbon reduction based on panel wattage, quantity, sun hours, and system efficiency.

Free online garbage classification lookup tool. Search and find the classification of common items across four categories: Recyclable, Kitchen Waste, Hazardous Waste, and Residual Waste. Master waste sorting knowledge with ease.

Free online paint calculator. Calculate paint quantity needed for interior walls, exterior walls, and primer based on room dimensions or wall area. Get recommended can counts for your painting project. Perfect for home renovation and wall refinishing.

Free online planting density calculator supporting rectangular, square, triangular and wide-narrow row planting patterns. Input row spacing and plant spacing to quickly calculate plants per mu/hectare for agricultural planning.

Free online fertilizer calculator. Calculate precise fertilizer amounts based on crop type, planting area, and fertilizer nutrient content. Supports multiple crop presets, common fertilizer types, and custom N-P-K ratios for scientific fertilization.

Free online irrigation water usage calculator supporting drip irrigation, sprinkler irrigation, surface irrigation and more. Scientifically calculate irrigation water requirements based on crop type, growth stage, and soil conditions for agricultural water conservation planning.

Free online planting schedule calculator. Enter your last frost date to automatically calculate indoor sowing, transplanting, and direct sowing dates for 30+ common vegetables. Perfect for garden planning and planting calendar.

Free online compost ratio calculator to help you calculate the carbon-to-nitrogen ratio (C:N) of compost materials. Supports common composting materials like dried leaves, straw, cardboard, grass clippings, kitchen scraps, coffee grounds, and more. Shows real-time whether the C:N ratio is in the ideal range.

Free online crop yield estimation tool supporting rice, wheat, corn, soybean and more. Input planting area, yield per unit area and other parameters to quickly estimate total crop yield. Perfect for agricultural production planning and harvest estimation.

Free online pesticide dilution calculator. Calculate pesticide dosage and water volume by dilution ratio or target concentration. Ideal for agriculture, gardening, and crop protection.

Free online aquarium volume calculator supporting rectangular, cylindrical, hexagonal, and custom shaped tanks. Real-time conversion between liters, US gallons, and UK gallons, with water weight, substrate, filter flow, and heater recommendations.

Free online earthquake magnitude comparison tool. Provides comparison of Richter scale, moment magnitude, surface wave magnitude, body wave magnitude and other magnitude standards, including magnitude classification, earthquake categories, typical damage levels and occurrence frequency.

Free online typhoon/hurricane category comparison tool. Provides comparison of Saffir-Simpson Hurricane Wind Scale (SSHWS), JMA, CMA, IMD and other major tropical cyclone classification systems, including wind speed ranges, typical damage levels and storm surge heights.

UV Index lookup and protection guide. Check real-time UV level meanings, risk levels, and protection recommendations to help you scientifically protect your skin health.

Comprehensive guide to brochure and print fold types including half fold, tri-fold, Z-fold, gate fold, French fold, accordion fold, cross fold, and more. Detailed descriptions, use cases, and panel information.

Free online beam deflection calculator supporting simply supported, cantilever, and fixed-end beams with point loads and uniformly distributed loads. Automatically calculates deflection, shear force, and bending moment with visual charts. Ideal for structural engineering analysis and education.

Free online 3D printing cost estimator. Input model dimensions, print parameters, and material costs to quickly estimate printing time, filament usage, and total cost. Supports PLA, ABS, PETG, TPU, and Resin. Ideal for FDM and SLA printers.

Free online wallpaper quantity calculator. Enter room dimensions (length, width, height) and wallpaper specifications to quickly calculate required rolls. Supports door/window deduction and pattern repeat calculation for renovation budgeting and wall covering material planning.

Free online stair tread design calculator. Input total rise and total run to automatically calculate number of steps, riser height, tread depth, stair angle, stringer length, and more. Supports metric/imperial units, building code compliance check. Perfect for indoor and outdoor stair design.

Free online net worth calculator. Quickly calculate personal or family net worth by entering assets (cash, deposits, investments, real estate, etc.) and liabilities (mortgage, car loan, credit card debt, etc.). Supports multiple currencies, real-time updates, easy to use.

Free online Chinese character Five Elements query tool. Enter Chinese characters to instantly look up the Wu Xing (Metal, Wood, Water, Fire, Earth) attribute of each character. Supports batch query, ideal for naming, Chinese character research, and traditional culture learning.

Free online Bazi (Four Pillars of Destiny) calculator. Automatically calculate Heavenly Stems, Earthly Branches, Hidden Stems, Nayin, Ten Gods, and Terrain based on birth date. Supports both Gregorian and Lunar calendar input.

Free online Zi Wei Dou Shu (Purple Star Astrology) chart calculator. Input your birth date and time to generate a complete Zi Wei astrological chart with 12 palaces, major and minor stars, transformations, and detailed destiny analysis.

Free online MIDI file viewer tool. Parse and browse detailed MIDI file information including track list, note events, tempo, time signature, and more. Quickly analyze MIDI music file structure without installation.

Free online audio decibel calculator supporting Sound Pressure Level (SPL) calculation, decibel addition, distance attenuation, dB-to-ratio conversion, sound intensity level calculation, and more. Ideal for audio engineering, acoustic design, noise assessment, and sound system tuning.

Free online optics calculator supporting lens formula, magnification, Snell's law, critical angle, lens power and other optical parameter calculations. Ideal for physics study, optical design and engineering applications.

Free online gear ratio calculator supporting single-stage gear ratio calculation, input/output RPM calculation, compound gear train ratio calculation, teeth ratio calculation, and more. Ideal for mechanical design, gear transmission system design, reducer design, and industrial drive applications.

Free online International Phonetic Alphabet (IPA) converter. Convert English text to IPA phonetic transcription in real-time. Supports both American English (en-US) and British English (en-GB) pronunciations with word-level breakdown. Includes a complete IPA chart reference with all vowel and consonant symbols.

Free online drug interaction checker tool. Search and check interactions between common medications including anticoagulants, statins, antihypertensives, antibiotics, antidepressants, and more. Get severity ratings and clinical recommendations.

Free online clinical laboratory reference values lookup tool. Covers 15+ categories and 200+ test items including blood routine, blood chemistry, liver function, renal function, lipid panel, myocardial enzymes, thyroid function, tumor markers, coagulation, urine routine, immunology, blood gas analysis, trace elements, and hormones. Supports gender filtering and test item search. Suitable for clinicians, medical students, lab technicians, and patients.

Free online first aid guide tool. Step-by-step instructions for CPR, Heimlich maneuver, bleeding control, fracture management, burn treatment, and other common emergency scenarios. Quick access to life-saving knowledge.

Free online academic plagiarism checker tool supporting text similarity detection, document content comparison, and duplicate ratio analysis. Enter two texts for real-time similarity comparison with highlighted duplicate content. Suitable for thesis checking, assignment verification, academic integrity inspection, and more.

Free online citation generator supporting APA, MLA, Chicago, Harvard, IEEE, GB/T 7714, and Vancouver formats. Auto-generate citations for journal articles, books, conference papers, websites, theses, and patents. One-click copy for academic writing and reference management.

Free online chemical structure drawing tool. Render and draw molecular structures from SMILES strings with common compound templates, supporting PNG and SVG export.

Free online dice probability calculator. Supports any number of dice and sides. Quickly calculate probabilities for specific sums or ranges, expected value, variance, and the full probability distribution. Perfect for tabletop games, TRPGs, and probability learning.

Free online poker probability calculator for Texas Hold'em. Enter your hole cards and community cards to calculate win, tie, loss and equity percentages in real time.

Free online speech timer with countdown and stopwatch modes, preset common speech durations, fullscreen display, sound alert and visual flash reminder. Perfect for meetings, classroom speeches, pitch presentations and more.

Free online Ishihara color blindness test. Detect red-green, blue-yellow color vision deficiencies and get a preliminary assessment.

Free online hearing test tool supporting left/right ear detection, pure-tone manual test and automatic threshold test, generates audiogram in real time to help you quickly understand your hearing condition.

Free online bolt torque calculator supporting metric (M4-M30) and imperial (1/4"-1") bolts. Calculate recommended tightening torque or preload based on strength grade, lubrication state and torque coefficient. Useful for mechanical assembly, automotive repair and engineering.

Free online pipe flow calculator. Calculate flow rate, Reynolds number, Darcy friction factor, head loss, and pressure drop from pipe diameter, velocity, or flow rate. Useful for plumbing, HVAC, and hydraulic engineering.

Free online heat conduction calculator. Calculate steady-state heat flow rate, heat flux and thermal resistance through a plane wall using Fourier's law, with material conductivity presets and unit switching.

Free online PCB trace width calculator based on the IPC-2221 standard. Quickly calculate the minimum trace width from current, temperature rise, copper thickness and trace location, plus resistance, voltage drop and power loss estimates.

Free online signal attenuation calculator supporting power attenuation, dBm/mW/W conversion, free-space path loss, cable attenuation, cascaded attenuation, wavelength calculation, and VSWR/return loss conversion for RF and networking engineering.

Free online battery life estimator. Enter battery capacity, device power consumption, and operating voltage to quickly calculate theoretical runtime on a full charge. Supports mAh/Wh and mA/W unit combinations.

Free online pump head calculator. Calculate the total dynamic head, friction losses, NPSHa, and pump power based on flow rate, pipe parameters, fittings, and elevation difference for water supply, HVAC, and industrial pump selection.

Free online concrete mix ratio calculator. Quickly get mix proportions by strength grade, or customize calculations based on design strength, aggregate type, slump, etc.