Free Number Base Converter that works offline
Convert integers among binary, octal, decimal, hexadecimal and custom bases without precision loss. BigInt arithmetic allows values larger than JavaScript’s ordinary safe integer range.
What this number base converter does
A number’s value stays constant while its written digits depend on the base. Every input digit must be smaller than the source base, and target letters can be returned in uppercase for conventional hex and base-36 notation.
How to use the Number Base Converter
- Enter or paste an integer and source and target bases from 2 to 36 into the tool.
- Adjust the available options so they match the format and result you need.
- Choose Convert base and review the exact integer representation in the target base before using it.
- Copy or download the result, then clear the page if the input was sensitive.
Common uses
- Inspecting binary and hexadecimal values
- Converting identifiers stored in base 36
- Learning positional number systems
- Checking large integer representations
Private processing and offline access
This tool does not submit your input to a conversion server. Processing takes place inside the browser using local JavaScript and standard Web APIs. After the PWA has been installed or cached, the page and its core features remain available without an internet connection. Closing or clearing the page removes unsaved input; the tool does not create an account or cloud history.
Tips for accurate results
- Enter integers only; decimal fractions require a different algorithm.
- Hexadecimal digits use A through F.
- Leading zeroes are removed because they do not change integer value.
Frequently asked questions
Does this tool upload my data?
No. Number Base Converter processes its input in the current browser and does not submit it to a conversion API.
What input does the Number Base Converter accept?
Positive and negative integers are accepted. Digits 0–9 and letters A–Z represent values through base 36; fractional values are not supported.
Can I use this tool offline?
Yes. Once the Offline Tools PWA has cached the page, the core feature works without an internet connection.