MoreOnlineTools
ESC

Number Base Converter

Convert numbers between Binary, Octal, Decimal, and Hexadecimal

Base Converter

Binary Base 2
Octal Base 8
Decimal Base 10
Hexadecimal Base 16

Custom Base Converter

Bit Representation

Enter a number to see its bit representation

Quick Reference Table

Decimal Binary Octal Hexadecimal
0 0 0 0
1 1 1 1
2 10 2 2
3 11 3 3
4 100 4 4
5 101 5 5
6 110 6 6
7 111 7 7
8 1000 10 8
9 1001 11 9
10 1010 12 A
11 1011 13 B
12 1100 14 C
13 1101 15 D
14 1110 16 E
15 1111 17 F
All processing happens in your browser. No data is sent to any server.

Usage Examples

Decimal to All Bases

Convert decimal 255 to see its binary (11111111), octal (377), and hexadecimal (FF) representations.

Binary Analysis

Enter a binary number like 11010110 and instantly see its value in decimal, octal, and hexadecimal.

Hex Color Values

Convert hex color values like FF00AB to binary and decimal for low-level color manipulation.

Features

Bidirectional Conversion

Type in any field and all other bases update instantly in real-time

Large Number Support

Handles arbitrarily large numbers using BigInt for precise conversions

Custom Base (2-36)

Convert between any two bases from 2 to 36 with the custom converter

Privacy First

All conversions happen locally in your browser, no data sent to servers

How to Use?

1

Enter a Number

Type a number in any of the four fields: Binary, Octal, Decimal, or Hexadecimal.

2

See Instant Results

The other three fields update automatically with the converted values in real-time.

3

Copy or Use Custom Base

Copy any result with one click, or use the custom base converter for bases 2-36.

Frequently Asked Questions

The main converter handles the four most common bases: Binary (base 2, digits 0–1), Octal (base 8, digits 0–7), Decimal (base 10, digits 0–9), and Hexadecimal (base 16, digits 0–9 and A–F). The custom converter handles any base from 2 to 36, using digits 0–9 and letters A–Z for bases above 10.

Each binary digit represents a power of 2 from right to left. For example, 1101 = 1×8 + 1×4 + 0×2 + 1×1 = 13. The tool does this instantly, but knowing the pattern helps when reading register values or debugging bit flags.

Hexadecimal needs 16 unique digits, so after 9 it uses letters: A=10, B=11, C=12, D=13, E=14, F=15. So FF in hex = 15×16 + 15 = 255 in decimal. Hex is widely used for color codes (#FF0000 = red) and memory addresses.

Yes. The converter uses JavaScript BigInt, so it handles arbitrarily large integers with no precision loss. Standard JavaScript numbers lose precision above 2^53, but BigInt avoids this for exact bit-level work.

Hexadecimal for color values (#RRGGBB), memory addresses, and byte representation. Binary for bit flags, bitmask operations, and understanding hardware registers. Octal for Unix file permissions (chmod 755). Base64 is a separate encoding, not a number base in this context.

Enter the number in the "Input Value" field, set the "From Base" (the base your number is currently in) and "To Base" (the target base), then click Convert. For bases above 10, digits use letters starting from A. For example, base 16 uses 0–F, base 36 uses 0–9 and A–Z.

The bit representation shows the binary value visually as colored bits, making it easy to see which bits are set (1) or cleared (0). Useful when working with flags, network masks, or bitwise operations in programming.

No. All conversions run entirely in your browser using JavaScript. Nothing is transmitted or stored anywhere.

What Is a Number Base Converter?

A tool that converts numbers between binary, octal, decimal, and hexadecimal -- the four bases developers deal with constantly. Type in one field, the others update instantly. There is also a custom converter for any base from 2 to 36.

Key Features

Real-time bidirectional conversion, BigInt support for arbitrarily large numbers, visual bit representation, custom base converter (2-36), input validation, and one-click copy.

Common Use Cases

Checking binary values when debugging hardware interfaces, converting hex color codes, working with octal file permissions, or just learning how different number systems relate to each other.

Tips

Hexadecimal uses digits 0-9 and letters A-F (case insensitive). For bases above 10, the custom converter uses letters beyond F up to Z for base 36.

Privacy

Everything runs in your browser with JavaScript. No data is transmitted to any server.

Security and Privacy

Your data security is our priority

Local Processing

All processing happens in your browser

No Data Transfer

Your data is not sent to our servers

No Data Storage

No data is stored or shared

SSL Encryption

SSL encryption for secure connection

Number Base Converter: Binary, Octal, Decimal & Hex Explained
Related Blog Post
Number Base Converter: Binary, Octal, Decimal & Hex Explained

Learn how number systems work, when to use binary, octal, decimal, and hexadecimal, and how to convert between them instantly.

Read Article 8 min read

Next Step

Binary to Text Converter

Convert between binary and text (ASCII/UTF-8)

ASCII Converter

Convert between ASCII, Text, Hex, Binary, Decimal

Related Tools

Epoch Converter

Convert Unix timestamps to dates and vice versa

Roman Numeral Converter

Convert between Roman numerals and decimal numbers

HTML to Markdown Converter

Convert HTML code to clean Markdown format with DOM parsing

JSON to YAML Converter

Convert JSON data to YAML format for configuration files

JSON to CSV Converter

Convert JSON data to CSV format with custom delimiters

Timestamp Converter

Unix timestamp, epoch time and timezone converter

Also on MoreOnlineTools

Free Online Tools

109 tools for text, images, security, development and more

Browse All Tools →
Developer Cheat Sheets

Quick reference for Regex, Git, HTTP codes, CSS, Markdown and more

Browse Cheat Sheets →
Online Calculators

BMI, loan, percentage, tip, age and more practical calculators

Browse Calculators →
Tool Collections

Curated workflows: API development, image pipeline, security audit and more

Browse Collections →