Number Base Converter

Convert numbers between binary, octal, decimal, hex and any base 2–36 — free and instant.

About

About the Number Base Converter

Converts a whole number in any base into binary, octal, decimal and hexadecimal all at once, plus a custom base from 2 to 36.

Students use it to check number-system homework, while developers use it to quickly convert a value while reading low-level code. It's one of many free data tools on Toolapt, and like every tool here, it's free to use with no sign-up and no limit on how many times you run it.

Choose what to view about this tool

Guide

Using the Number Base Converter

  1. 1

    Step 1

    Type a number into the Value field.

  2. 2

    Step 2

    Choose which base that number is written in.

  3. 3

    Step 3

    Read the result in binary, octal, decimal and hexadecimal all at once.

  4. 4

    Step 4

    Optionally set a custom base (2–36) to see the value converted into that base too.

  • Converts to binary, octal, decimal and hexadecimal simultaneously, not one at a time
  • Supports any custom base from 2 to 36, not just the four common ones
  • Updates every result live as you type or change the input base
  • Works entirely in your browser — no installs and no sign-up
  • Free to use, with no limit on how many times you run it
  • Fully responsive, so it works just as well on a phone as on a desktop

Students learning number systems

Students learning number systems use the Number Base Converter for checking binary, octal and hex homework answers.

Developers

Developers use the Number Base Converter for quickly converting a value while reading low-level code or debugging bit flags.

Networking and hardware engineers

Networking and hardware engineers use the Number Base Converter for translating addresses and register values between bases.

Puzzle and competitive-programming enthusiasts

Puzzle and competitive-programming enthusiasts use the Number Base Converter for working with unusual custom bases quickly.

Examples

Number Base Converter examples

3 worked examples

01

Decimal to everything

Entering 255 as decimal shows it as 11111111 in binary, 377 in octal, and FF in hexadecimal, all at once.

02

Hex value from code

Entering 1F4 as hexadecimal shows a decimal equivalent of 500.

03

Custom base 5

Entering 255 (decimal) with custom base 5 shows 2010, since 255 = 2×125 + 0×25 + 1×5 + 0.

Related tools

CSV and JSON Converter

Turn CSV into JSON records, or JSON records back into CSV.

Use it

Query String Parser

Split a URL into readable parameters, and build a query string back from them.

Use it

Hash Generator

SHA-1, SHA-256, SHA-384 and SHA-512 checksums of any text.

Use it

String Escape and Unescape

Escape text for use inside a JavaScript or JSON string literal, or reverse it.

Use it

ISBN Validator and Converter

Validate a book's ISBN-10 or ISBN-13 checksum and convert between the two formats.

Use it

File Hash Calculator

Compute SHA-256, SHA-384 or SHA-512 checksums of a file without uploading it.

Use it

FAQ

Frequently asked questions

Quick answers to common questions about the Number Base Converter.

What does the Number Base Converter do?

It converts a whole number from any base into binary, octal, decimal and hexadecimal at once, plus a custom base of your choice from 2 to 36.

Is the Number Base Converter free to use?

Yes. It's free, with no sign-up, no watermark and no limit on how many times you use it.

Is my input safe when I use this tool?

Yes. The number you type is processed entirely on your own device — nothing is sent to a server.

What bases can I convert from?

Binary (2), octal (8), decimal (10), hexadecimal (16) or base 36 — pick any of these as your input base.

Can I convert to a base other than the four common ones?

Yes. Enter any base from 2 to 36 in the "Custom base" field to see the value converted into that base.

Does it support negative numbers or decimals?

It's built for whole, non-negative numbers — the kind most base-conversion tasks need.

Can I use the Number Base Converter on my phone?

Yes. The page is fully responsive and works on mobile, tablet and desktop browsers alike.

Does the Number Base Converter have any limitations?

Extremely large numbers are limited by your browser's own number precision rather than a fixed digit cap.

Still have a question? Contact us

Report a problem

Number Base Converter

What went wrong?
    or paste a screenshot