GOAT LabOmniConvert: unit converter for 35 measurement categories
OmniConvert is a free, browser-only unit converter covering 35 measurement categories and 324 units, from SI base units to historical, regional, and astronomical scales. It runs fully client-side with no backend, no sign-up, and works offline.
- Free
- No sign-up
- Works offline
What is OmniConvert?
OmniConvert is a static unit converter that turns one quantity into another within the same physical dimension. It spans 35 categories (length, mass, temperature, energy, pressure, data, and more) with 324 units, applying exact conversion factors such as 1 atm = 101,325 Pa and 1 KiB = 1024 B.
How does it work?
Each conversion routes a value through the category base unit (meter, kelvin, joule, pascal, bit, etc.) using base = value x factor + offset, then solves for the target unit. SI prefixes (kilo, mega, milli, nano) scale the result; temperature and other absolute scales disable prefixes.
When should I use it?
Use OmniConvert when you need an exact unit conversion across science, engineering, or everyday tasks: SI to imperial, kelvin to Celsius, joule to electronvolt, bytes to KiB, or astronomical units to meters. It is ideal offline since the whole tool is static and cached locally.
At a glance
| Categories / units | 35 categories, 324 units |
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| SI prefixes | yotta (10^24) to yocto (10^-24), 20 decimal prefixes |
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| Temperature scales | 8: K, C, F, Rankine, Reaumur, Delisle, Newton, Romer |
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| Speed of light (light-second) | 299,792,458 m (exact) |
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| Astronomical unit | 149,597,870,700 m (2012 IAU exact) |
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| Standard atmosphere | 1 atm = 101,325 Pa (exact) |
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| Electronvolt | 1 eV = 1.602176634e-19 J |
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| Binary data | 1 KiB = 1024 B; 1 kB = 1000 B |
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Frequently asked questions
How many units and categories does OmniConvert support?
OmniConvert covers 35 measurement categories with 324 individual units, grouped into Basic, Mechanics, Electromagnetism, Chemistry, Optics, Fluid, Information/Data, and Other.
Which SI prefixes are available?
All 20 SI decimal prefixes, from yotta (10^24) down to yocto (10^-24), plus a 'none' option. IEC binary prefixes (Ki, Mi, Gi, Ti, Pi, Ei = 2^10 to 2^60) are available in the Information category as distinct units like KiB and MiB.
What temperature scales can it convert?
Eight absolute temperature scales: Kelvin, Celsius, Fahrenheit, Rankine, Reaumur, Delisle, Newton, and Romer. Water freezes at 273.15 K = 0 C = 32 F and boils at 373.15 K = 100 C = 212 F.
Does OmniConvert work offline and need an account?
Yes, it works offline and needs no account. It is a fully static, browser-only app with no backend; a service worker caches the shell so conversions run without a network connection.
Can I share or bookmark a specific conversion?
Yes. The current category, source unit, prefix, and value are encoded in the URL hash (keys c/fu/fp/fv/tu/tp), so any conversion can be bookmarked or shared as a link.
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