Study number systems
Students use a binary to decimal converter and a decimal to binary converter to check number-system homework and exam practice.
A LITTLE CLARITY FOR YOUR BITS
Binary Converter
Text, binary, decimal, hex and octal. See the result as you type, right in your browser.
Free to useNo signupPrivate by design
> 01 SEE THE PATTERN
Binary to text & text to binary examples
These examples show how to convert binary to text and how to convert text to binary with a few clicks. Binary uses just two digits: 0 and 1. In text mode, each group of 8 bits represents one UTF-8 byte. The ASCII characters below each use one byte; other characters can use several.
| Text | Binary (UTF-8 bytes) |
|---|---|
| HiA short greeting | |
| BinarySix ASCII characters | |
| 101The text “101”, not the number |
Text or number? The text “101” is three characters, so it uses three bytes. The binary number 101 is a single integer with decimal value 5.
> 02 HOW IT WORKS
How to convert binary to text
Start with 01001000 01101001. Here’s how those bits become a greeting.
01
Split into bytes
Separate 01001000 01101001 into complete 8-bit groups.
02
Read each value
The two byte groups represent decimal 72 and 105.
03
Decode the text
In ASCII and UTF-8, 72 is H and 105 is i.
04
Put it together
Read the characters in order to get Hi.
> 02B REVERSE THE DIRECTION
How to convert text to binary
Start with a message such as Hi, then encode each UTF-8 byte.
01
Start with your text
Enter a message such as Hi. Spaces and line breaks count too.
02
Encode it as UTF-8
H becomes byte 72 and i becomes byte 105. Emoji can use several bytes.
03
Write each byte in binary
72 becomes 01001000 and 105 becomes 01101001.
04
Join the byte groups
Separate the groups with spaces to get 01001000 01101001.
> 03 READ THE BITS
How to read binary by hand
Binary code looks intimidating, but each 0 and 1 is just a power of two. When you read one 8-bit text byte from right to left, the positions stand for 128, 64, 32, 16, 8, 4, 2 and 1.
Take the letter “H.” In ASCII—and therefore in UTF-8—it is one byte with decimal value 72. Written in binary, it is 01001000. Add the value of every position that holds a 1: 64 + 8 = 72. That matches the value for H, so the binary to text converter returns “H.”
0100100064 + 872HThe same place-value logic powers number conversion here. A binary to decimal converter adds the powers of two selected by the 1s. A decimal to binary converter works in the other direction by repeatedly dividing by two and reading the remainders in reverse.
When the text to binary converter turns text into binary code, it first encodes the text as UTF-8 bytes and writes every byte in the eight-bit form above. Try it with an uppercase letter from your name: find it in the table below, add the powers of two, and you will get the same byte the tool produces.
> 04 KEEP IT HANDY
Binary, decimal and hex quick reference
The same whole number, written three ways. These are integers, so no extra leading zeros are added.
| Decimal Base 10 | Binary Base 2 | Hex Base 16 |
|---|---|---|
0 | 0 | 0 |
1 | 1 | 1 |
2 | 10 | 2 |
3 | 11 | 3 |
4 | 100 | 4 |
5 | 101 | 5 |
6 | 110 | 6 |
7 | 111 | 7 |
8 | 1000 | 8 |
9 | 1001 | 9 |
10 | 1010 | A |
11 | 1011 | B |
12 | 1100 | C |
13 | 1101 | D |
14 | 1110 | E |
15 | 1111 | F |
16 | 10000 | 10 |
32 | 100000 | 20 |
64 | 1000000 | 40 |
127 | 1111111 | 7F |
128 | 10000000 | 80 |
255 | 11111111 | FF |
Common ASCII to binary reference
Use this table to decode or encode common uppercase letters without opening the tool. Each group shows the character, its ASCII decimal value and its eight-bit binary code. These values are also the corresponding one-byte UTF-8 encodings.
| Char | Dec | Binary | Char | Dec | Binary | Char | Dec | Binary |
|---|---|---|---|---|---|---|---|---|
| A | 65 | 01000001 | J | 74 | 01001010 | S | 83 | 01010011 |
| B | 66 | 01000010 | K | 75 | 01001011 | T | 84 | 01010100 |
| C | 67 | 01000011 | L | 76 | 01001100 | U | 85 | 01010101 |
| D | 68 | 01000100 | M | 77 | 01001101 | V | 86 | 01010110 |
| E | 69 | 01000101 | N | 78 | 01001110 | W | 87 | 01010111 |
| F | 70 | 01000110 | O | 79 | 01001111 | X | 88 | 01011000 |
| G | 71 | 01000111 | P | 80 | 01010000 | Y | 89 | 01011001 |
| H | 72 | 01001000 | Q | 81 | 01010001 | Z | 90 | 01011010 |
| I | 73 | 01001001 | R | 82 | 01010010 | | |
Digits 0–9 run from 00110000 (48) to 00111001 (57), and lowercase letters run from 01100001 (97) for “a” to 01111010 (122) for “z.” The binary to text converter and text to binary converter produce the same byte values for ASCII characters; other UTF-8 characters can use more than one byte.
> 05 PUT IT TO WORK
When do you need a binary converter?
Most people land here with one of four jobs in mind.
Decode text bytes
Developers debugging logs or low-level data can turn valid ASCII or UTF-8 byte strings back into readable text without installing anything.
Check network values
Network students and engineers can check individual IPv4 octet and subnet-mask values in binary, one whole number at a time.
Compare hex and binary
CTF players and electronics hobbyists regularly compare whole-number hex and binary values while reading simple opcodes and data sheets.
Whatever your reason, the workflow is the same: pick the direction, paste your input and read the result as you type. Bookmark this page so you can turn text into binary code—or decode it back—whenever you need it.
> 06 A FEW GOOD QUESTIONS
Binary Converter FAQ
What is a binary converter?
A binary converter translates between binary code (0s and 1s) and formats such as text, decimal, hex and octal. This tool supports UTF-8 text and non-negative whole numbers.
How do I convert binary to text?
To convert binary to text, choose Binary as the source and Text as the target. Paste 8-bit bytes, separated by spaces or joined together, and the result appears automatically. The bytes must form valid UTF-8 text. For example, 01001000 01101001 becomes Hi.
Can I convert text to binary with this tool?
Yes. To convert text to binary, choose Text as the source and Binary as the target, then enter your message. The text to binary converter encodes your text as UTF-8 and writes every byte as an eight-bit binary group as you type. Some characters, including Chinese characters and emoji, use more than one byte.
Is this binary converter free?
Yes. You can use every conversion in this tool for free, without an account. Each input is limited to 65,536 UTF-16 units, and number mode accepts up to 4,096 digits per integer to keep the browser responsive.
Does this binary converter work offline?
Once the page and its interactive tool have finished loading, conversion runs locally and continues to work without an internet connection. Opening or reloading the website still requires a connection; this is not an installed offline app.
How do I convert binary to decimal?
Choose Binary as the source and Decimal as the target. Enter one whole binary number, such as 1010, and the result automatically updates to 10. Number mode does not require 8-bit groups and does not accept spaces between digits.
How do I convert decimal to binary?
Choose Decimal as the source and Binary as the target. Enter a non-negative whole number, such as 13, to get 1101. Results use only the digits needed, without extra leading zeros. Negative numbers, fractions and scientific notation are not supported in this version.
Can I convert ASCII and UTF-8 text?
Yes. ASCII characters such as H use one UTF-8 byte. Characters such as 中 use three bytes, and 😀 uses four. Spaces, tabs and line breaks are preserved. Invalid UTF-8 is reported as an error instead of being silently replaced.
Do I need to install an app or sign up?
No. The converter works directly in your browser without installation or an account. Your input is processed on your device and is not uploaded by the tool.