Number System Converter
Binary, hexadecimal, octal, decimal and file size conversions
Understanding number systems
Computers use binary (base 2) internally, but developers often work with hexadecimal (base 16) because it is more compact. Decimal (base 10) is our everyday system, and octal (base 8) is used in some Unix contexts.
Why hexadecimal in computing?
One byte (8 bits) can be represented by exactly 2 hexadecimal digits (00 to FF). That is why web colors (#FF5733), MAC addresses and error codes are in hex. FF hex = 255 decimal = 11111111 binary.
File size conversions
1 KB = 1,024 bytes | 1 MB = 1,048,576 bytes | 1 GB = 1,073,741,824 bytes. Note: hard drive manufacturers use 1 GB = 1,000,000,000 bytes, which explains the difference between advertised and actual capacity.
Why choose OmniTools?
OmniTools brings together 20+ carefully crafted online tools built by our team. Every tool is designed to be fast, accurate and usable without sign-up. We believe essential everyday utilities — calculators, converters, generators — should be freely available with a clean interface and no intrusive ads. Our commitment: your data never leaves your browser.
Our tools are used daily by students, real-estate professionals, developers, designers, travelers and curious minds. Each tool comes with detailed documentation, formulas, reference values and practical tips to help you get the most out of it. We regularly ship new tools and improvements based on community feedback.
Frequently asked questions
Is this tool really free?
Yes, OmniTools is completely free, with no sign-up and no usage limit. No credit card required.
Is my data sent to a server?
No. All calculations and conversions run in your browser. Your data stays private on your device.
Does it work on mobile?
Yes, the interface is fully responsive and optimized for smartphones, tablets and desktops.
How often is the tool updated?
We continuously improve our tools based on user feedback to guarantee accuracy and reliability.