Every tool you need. Nothing you don't.
A growing library of fast, focused web utilities — free to use, no account required, and built to stay out of your way.
Start typing to search…
At a glance
1200+
Tools available
100%
Free to use
0
Sign-ups needed
Instant results
Most tools run in your browser for speed and privacy.
Private by default
Your inputs stay on your device — we don't store them.
Fresh additions
Recently Added
The latest tools added to our collection
Bond Order Calculator
Calculate the bond order of molecules using molecular orbital theory. Free online bond order calculator for chemistry students and professionals.
Boiling Point Elevation Calculator
Calculate the boiling point elevation of solutions using molality, ebullioscopic constants, and Van't Hoff factor. Free online boiling point elevation calculator for chemistry.
Boiling Point at Altitude Calculator
Calculate the boiling point of water at any altitude above sea level. Free online boiling point at altitude calculator using standard atmospheric pressure formulas.
Boiling Point Calculator
Calculate the boiling point of water and common substances at any pressure using the Clausius-Clapeyron equation. Free online boiling point calculator with support for multiple substances.
Bleach Dilution Calculator
Calculate the exact amount of bleach and water needed for disinfection, pool maintenance, and water purification. Free online bleach dilution calculator.
Beer Lambert Law Calculator
Calculate absorbance, transmittance, concentration, path length, or molar absorptivity using Beer-Lambert law. Free online Beer's law calculator for spectroscopy.
Avogadro Number Calculator
Calculate the number of atoms or molecules in any substance using Avogadro's number. Free online Avogadro's constant calculator for chemistry.
Average Atomic Mass Calculator
Calculate the average atomic mass of elements from isotope masses and natural abundance percentages. Free online average atomic mass calculator for chemistry.
Atomic Mass Calculator
Calculate the atomic mass of any atom from its number of protons and neutrons. Get results in atomic mass units (amu) and kilograms.
Atom Economy Calculator
Calculate the atom economy of chemical reactions. Measure how efficiently reactants are converted to desired products in green chemistry.
Atom Calculator
Calculate the number of protons, neutrons, and electrons in any atom or ion. Enter atomic number, mass number, and charge to find atomic composition.
Arrhenius Equation Calculator
Calculate the rate constant of a chemical reaction using the Arrhenius equation with activation energy, temperature, and pre-exponential factor.
Alligation Calculator
Calculate the ratio and volumes needed to mix two solutions of different concentrations to obtain a desired intermediate concentration.
AFR Calculator
Calculate the stoichiometric air-fuel ratio for common fuels including methane, propane, octane, hydrogen, and more with customizable fuel composition.
Activity Coefficient Calculator
Calculate the activity coefficient of an ion in dilute solution using the Debye-Huckel limiting law with ionic strength and charge number.
Activation Energy Calculator
Calculate activation energy (Ea) for chemical reactions using the Arrhenius equation. Free online activation energy calculator with support for temperature, rate constant, and frequency factor inputs.
Water Soluble Fertilizer Calculator
Calculate how much water soluble fertilizer to add for target ppm concentrations. Free online fertilizer calculator for hydroponics, greenhouse crops, and custom nutrient solution mixing.
Water Potential Calculator
Calculate water potential (Psi) by summing osmotic potential, pressure potential, and gravitational potential components with our free online water potential calculator for plant physiology and soil science.
Wastewater Calculator
Calculate key wastewater treatment parameters including BOD loading, F/M ratio, hydraulic retention time (HRT), mean cell residence time (MCRT), sludge age, and sludge volume index (SVI) with our free online wastewater calculator.
Vegetable Yield Calculator
Calculate your vegetable garden yield based on crop type, row length, and number of rows. Plan your garden with our free online vegetable yield estimator.
Vegetable Seed
Calculate how many vegetable seeds or seedlings you need for your garden rows. Free online vegetable seed calculator with preset spacing for common vegetables.
Vapor Pressure Deficit
Calculate vapor pressure deficit (VPD) for optimal plant growth with our free online VPD calculator. Input temperature and humidity to determine the ideal growing environment.
Turtle Tank
Calculate the ideal tank size for your turtle based on species and shell length. Free online turtle tank calculator helps ensure your pet has adequate swimming space.
Trihybrid Cross Punnett Square
Calculate trihybrid cross Punnett square for 3 traits with our free online genetics calculator. Analyze genotype and phenotype probabilities for offspring with 64-box Punnett square.
Explore the library
Browse by Category
39 categories — pick one to explore its tools
ASCII Tools
26 tools
Audio & Video Tools
28 tools
Biology
37 tools
Color Tools
42 tools
Construction & Real Estate
41 tools
Data Conversion
85 tools
Developer Tools
227 tools
Education Tools
7 tools
Electrical & Electronics
20 tools
Encoding & Encryption
80 tools
Engineering Fluid Mechanics
53 tools
Finance Calculators
252 tools
Food Cooking
19 tools
Fractal Generators
45 tools
Gaming Tools
32 tools
Health & Fitness
100 tools
Image Manipulation
125 tools
List Tools
46 tools
Math Calculators
401 tools
Miscellaneous tools
28 tools
Name Generators
11 tools
Network Tools
25 tools
Paycheck Calculators
51 tools
PDF & Document Tools
3 tools
Physics & Chemistry
80 tools
QR & Barcode Tools
5 tools
Random Generators
70 tools
Real Estate Finance
27 tools
Social Media Tools
20 tools
Statistics & Data Analysis
48 tools
Text Editors & Viewers
6 tools
Text Processing
91 tools
Time & Date
112 tools
Travel & Automotive
19 tools
Unicode Tools
43 tools
Unit Converters
57 tools
Utilities
34 tools
Weather & Environment
7 tools
Web & SEO Tools
22 tools
No categories match your search.
On the roadmap
Coming Soon
New mini-tools we're building next.
Html to Jsx
Convert HTML file to JSX online
Instagram Reel Downloader
Download and save Instagram videos locally with our Instagram Reel Downloader. No signup required.
Instagram Reel Thumbnail Downloader
Save thumbnails from any reel
Always free
No subscriptions, credits, or paywalls. Every tool on the site is free to use.
Privacy first
Processing happens client-side whenever possible. Your data never leaves your browser.
Organized by category
Browse by topic or search instantly. Find the right utility in seconds.
Support
Frequently Asked Questions
Straight answers about how Online Mini Tools works.
Are the tools on this website free to use?
Do I need to create an account to use the tools?
Can I suggest new tools or features?
Are the results generated by these tools accurate?
Are my inputs and results private and secure?
Are these tools compatible with mobile devices?
Have an idea?
Didn't find the tool you need?
We're always expanding the collection. Tell us what would make your workflow easier and we'll consider it for the roadmap.
Browser Extension
Get the Online Mini Tools Browser Extensions
Search and launch any tool from your browser toolbar — available for Chrome and Firefox. Access 1200+ tools without leaving your current tab.
Google and the Chrome Web Store badge are trademarks of Google LLC. Firefox and the Firefox Add-ons logo are trademarks of the Mozilla Foundation.