Base Converter: Convert Binary, Octal, Decimal, Hex Online

Convert integers between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16). See all four representations at once, with conversion handled in the browser.

Real-time conversion between binary (2), octal (8), decimal (10), and hexadecimal (16): Results update as the input value, source base, or target base changes.
All Bases at a Glance grid shows all four representations at once: The same integer is displayed in binary, octal, decimal, and hexadecimal without changing settings.
One-click swap button reverses source and target bases: The current result becomes the new input when the conversion direction is swapped.
Supports negative integers and values up to 2^53 - 1 (9,007,199,254,740,991): Fractional values and base prefixes such as 0b, 0o, and 0x are not supported.
Browser-based conversion: Number parsing and conversion use JavaScript on the current page.

Value

From Base

Result

To Base

All Bases at a Glance

Binary —

Octal —

Decimal —

Hexadecimal —

How to Use This Base Converter

Enter your number: Type any integer in the "Value" field. Valid characters depend on the selected source base: 0–1 for binary, 0–7 for octal, 0–9 for decimal, and 0–9 plus A–F for hexadecimal. Do not include prefixes like 0b, 0o, or 0x.
Select source and target bases: Choose from the "From Base" and "To Base" dropdowns. The converted result updates as you type. Use the swap button (⇄) to reverse the direction and continue converting.
View all representations at once: The "All Bases at a Glance" grid below the converter shows your number in binary, octal, decimal, and hexadecimal at the same time, without switching settings.
Fix invalid input: If you enter an invalid character for the selected base, such as "2" in binary mode, the tool shows an error. Correct the input and the result refreshes automatically.

Practical Applications

Debugging color codes: Convert CSS hex color values to decimal RGB components. For example, enter FF in hexadecimal mode to get 255 — the maximum value for a single color channel in CSS. Use this when writing JavaScript that manipulates canvas pixels or when matching colors between design tools and code.

Working with file permissions: Unix file permissions are commonly shown in octal (e.g. 755). Enter 755 in octal mode to see it as binary 111101101, where each triplet shows the read/write/execute bits for owner, group, and others. Common values: 777 (full access), 644 (read-only for group/others), 700 (owner only).

Reading memory addresses: Memory addresses and debug logs frequently use hexadecimal notation. Convert hex values like 7FFF to decimal (32,767) or binary to inspect the numeric range or bit layout during low-level debugging.

Learning number systems: Computer science students can enter any decimal number and see its binary, octal, and hexadecimal equivalents. Start with small values like 10, 42, or 255 to build intuition, then work up to larger numbers. The All Bases grid makes it easy to compare representations side by side.

Parsing network addresses: MAC addresses (00:1A:2B:3C:4D:5E) and IPv6 addresses use hexadecimal notation. Each hex pair in a MAC address represents one byte — convert 1A to decimal 26 or binary 00011010 to understand the device identifier structure.

FAQ

Q. How do I convert binary to decimal?

Enter your binary number (using only 0s and 1s), select "Binary (2)" as the From Base and "Decimal (10)" as the To Base. The result appears as you type. You can also see the decimal value in the "All Bases at a Glance" grid without changing any settings.

Q. What number bases does this converter support?

This tool supports four number systems: 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). Each representation appears in the "All Bases at a Glance" grid.

Q. Can I convert negative numbers between bases?

Yes. Type a minus sign before your number and the converter will display the signed result across all four bases. For example, entering -255 in decimal shows -11111111 in binary, -377 in octal, and -FF in hexadecimal.

Q. How do I convert a hex color code to decimal RGB values?

Remove the # prefix and convert each two-character pair separately. For #FF6600, convert FF to decimal (255) for the red channel, 66 to decimal (102) for green, and 00 to decimal (0) for blue. This tool handles one value at a time, so enter each pair individually.

Q. What is the largest number this base converter can handle?

The maximum supported value is 2^53 - 1 (9,007,199,254,740,991 in decimal). Numbers beyond this limit may lose precision because JavaScript uses 64-bit floating-point representation for all numbers.

About the Base Converter

Convert integers between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16). Enter a value in one number system and see the equivalent value in the other three in the All Bases at a Glance grid. Results update as you type.

The converter supports negative integers and handles values up to 2^53 - 1 (9,007,199,254,740,991 in decimal). A one-click swap button reverses the source and target bases and uses the current result as the next input. Calculations use JavaScript number conversion on the current page.

Use it for debugging hex color codes, parsing Unix file permissions, learning number systems, or reading MAC and IPv6 addresses.

Supported Formats

Base	Name	Valid Characters	Common Use
2	Binary	0, 1	Digital logic, bit flags
8	Octal	0–7	Unix file permissions
10	Decimal	0–9	Everyday arithmetic
16	Hexadecimal	0–9, A–F	Color codes, memory addresses

When to Use This Base Converter

Converting CSS hex colors to RGB: Translate hex color values like #FF6600 into decimal RGB components (255, 102, 0) for use in JavaScript canvas operations, CSS rgb() functions, or design tool color pickers. Enter each two-character hex pair to get the corresponding decimal value.
Reading Unix and Linux file permissions: Octal permission codes such as 755 or 644 map directly to read/write/execute bits. Convert 755 to binary to see the bit pattern 111101101, or convert the value to hexadecimal for use in configuration files and scripts.
Decoding memory addresses in debug logs: Crash dumps, stack traces, and memory-mapped I/O registers often contain hexadecimal addresses like 0x7FFF5FBFF8C8. Convert to decimal to calculate offsets or to binary to inspect the bit-level layout of the address space.
Completing computer science coursework: Digital logic, computer architecture, and assembly language exercises often require number-base conversion. Practice by entering common decimal values (8, 16, 32, 64, 128, 255, 256, 1024, 65535) and comparing their binary, octal, and hex equivalents.
Parsing network protocol headers: Packet captures, MAC addresses, and IPv6 addresses often use hexadecimal data. Each hex digit maps to exactly 4 binary bits, which helps when reading protocol fields or troubleshooting connectivity issues.
Verifying bitmask calculations: Embedded systems programmers and game developers often work with bit flags and bitmasks. Convert between hexadecimal and binary to verify that bit-level operations (AND, OR, XOR) produce the expected results before applying them in code.

Common Number Conversions Reference

Decimal	Binary	Octal	Hex	Description
2	10	2	2	Binary base unit
8	1000	10	8	Octal base unit
10	1010	12	A	Decimal base
16	10000	20	10	Hexadecimal base unit
32	100000	40	20	5-bit maximum + 1
64	1000000	100	40	6-bit maximum + 1
128	10000000	200	80	7-bit maximum + 1
255	11111111	377	FF	8-bit maximum (1 byte)
256	100000000	400	100	2^8
1024	10000000000	2000	400	1 KB
65535	1111111111111111	177777	FFFF	16-bit maximum
493	111101101	755	1ED	Unix permission: rwxr-xr-x

Tips for Using This Base Converter

Integers only: This converter handles whole numbers only. Fractional values are not supported because converting fractions between bases can produce repeating digit sequences.
No prefixes needed: Do not include prefixes like 0b (binary), 0o (octal), or 0x (hexadecimal). The tool determines the number system from the "From Base" dropdown selection, so prefixes will trigger an invalid character error.
Negative numbers are supported: Add a leading minus sign before your number. The converter treats it as a signed integer and displays the negative result across all four bases. For example, -255 in decimal becomes -FF in hexadecimal.
Use the swap button for reverse conversions: Instead of retyping the result and changing both dropdowns, click the swap button (⇄) to reverse the direction. The current result becomes the new input automatically.
Maximum value is 2^53 - 1: The largest supported value is 9,007,199,254,740,991 (decimal). Values exceeding this limit may lose precision due to JavaScript's 64-bit floating-point number representation.
In-browser processing: Number parsing and conversion run on the current page using JavaScript. No upload is required to calculate an entered number.