All Free Tools
8,451 free online tools across 85 categories
Every tool here runs in your browser — no sign-up, no upload, nothing to install. Convert files, format code, generate text, run calculations, and check SEO across PDF, image, developer, finance, and unit-conversion tools. Pick one and start.
| Tool | Category | Description | Action |
|---|---|---|---|
|
Opus to FLAC Converter
|
Audio Tools | Open | |
|
Opus to M4A Converter
|
Audio Tools | Open | |
|
Opus to MP3 Converter
|
Audio Tools | Open | |
|
Opus to OGG Converter
|
Audio Tools | Open | |
|
Opus to WAV Converter
|
Audio Tools | Open | |
|
Opus to WMA Converter
|
Audio Tools | Open | |
|
ORBIT Bleeding Score
|
Health & Fitness | Open | |
|
Orbital Eccentricity Calculator
|
Space & Astronomy | Open | |
|
Orbital Mechanics Calculator
|
Physics Tools | Open | |
|
Orbital Period Calculator
|
Space & Astronomy | Open | |
|
Orbital Period Calculator (Kepler's Third Law)
|
Physics Tools | Open | |
|
Orbital Velocity Calculator
|
Aerospace Tools | Open | |
|
Orbital Velocity Calculator
|
Science Tools | Open | |
|
Orc Name Generator
|
Generators | Open | |
|
Orchard Tree Density Calculator
|
Agriculture Tools | Open | |
|
Order of Operations Helper
|
Education | Open | |
|
Ordinal Number Converter
|
Text Tools | Open | |
|
Ordinal Number Converter
|
Language Tools | Open | |
|
Ore Grade Calculator
|
Engineering Tools | Open | |
|
Orifice Flow Calculator
|
Chemistry Tools | Open | |
|
Original Gravity Calculator
|
Food & Cooking | Open | |
|
Osmium Electron Configuration
|
Chemistry Tools | Open | |
|
Osmium Oxidation States
|
Chemistry Tools | Open | |
|
Osmolarity of IV Fluid Calculator
|
Health & Fitness | Open | |
|
Osmotic Pressure Calculator
|
Chemistry Tools | Open | |
|
Oswestry Disability Index (ODI) Calculator
|
Health & Fitness | Open | |
|
Ottawa Ankle Rule
|
Health & Fitness | Open | |
|
Ottawa Knee Rule
|
Health & Fitness | Open | |
|
Otto Cycle Efficiency
|
Physics Tools | Open | |
|
Ounces to Carats Converter
|
Unit Converters | Open | |
|
Ounces to Cups Converter
|
Unit Converters | Open | |
|
Ounces to Grains Converter
|
Unit Converters | Open | |
|
Ounces to Grams Converter
|
Unit Converters | Open | |
|
Ounces to Grams Converter (Cooking)
|
Unit Converters | Open | |
|
Ounces to Grams Converter (oz to g, gold and food)
|
Unit Converters | Open | |
|
Ounces to Kilograms Converter
|
Unit Converters | Open | |
|
Ounces to Micrograms Converter
|
Unit Converters | Open | |
|
Ounces to Milligrams Converter
|
Unit Converters | Open | |
|
Ounces to Pounds Converter
|
Unit Converters | Open | |
|
Ounces to Pounds Converter (Cooking)
|
Unit Converters | Open | |
|
Ounces to Stones Converter
|
Unit Converters | Open | |
|
Ounces to Tablespoons Converter
|
Unit Converters | Open | |
|
Ounces to Teaspoons Converter
|
Unit Converters | Open | |
|
Ounces to Tonnes Converter
|
Unit Converters | Open | |
|
Out-of-Pocket Max Calculator
|
Insurance Tools | Open | |
|
Oven Spring Helper
|
Baking Tools | Open | |
|
Oven Temperature Converter
|
Food & Cooking | Open | |
|
Overshoot Calculator
|
Engineering Tools | Open |
Showing 5,233–5,280 of 8,451 tools