Input
Preparing your workspace…
How to use
- Enter a decimal value, or paste one value per line.
- Read the binary result; adjust fraction precision if needed.
- Copy binary digits, or swap to convert them back.
Reading decimal values as bits
Binary uses powers of two instead of powers of ten. A decimal value such as 42 becomes 101010 because 32 + 8 + 2 equals 42.
This page starts with decimal input and binary output. It is useful for inspecting numeric flags, comparing values and checking bit patterns before choosing a fixed machine width.
Representations and workflow
The integer portion is repeatedly divided by two to determine its binary digits. Leading zeros in the source do not set a bit width; the result uses the shortest magnitude representation.
4210101042 = 32 + 8 + 2, so the corresponding binary positions are set.
Precision and validation
A decimal fraction may not have a finite binary expansion. For example, 0.1 repeats in base two. Truncated results are marked rather than presented as exact.
Interpreting and reusing the result
Negative numbers retain a minus sign. They are not silently converted to two’s complement. Use the Bitwise Calculator when a signed 8-, 16-, 32-, 64-, 128- or 256-bit pattern is required.
Numbers: up to 500 lines / 1 MiB, at most 4,096 characters per numeral. Fraction output: 1–128 digits. Text and byte data: 64 KiB. Bitwise operations: 8–256 bits. Workers stop after 30 seconds; inputs are not uploaded.
Frequently asked questions
Does the result always have eight bits?
No. This converter returns a minimal magnitude representation. It does not add zero padding or assume a machine width.
How are negative decimal numbers converted?
The magnitude is converted to binary and the minus sign is retained. Fixed-width two’s complement is a separate operation.
Can I enter 1e6?
No. Enter 1000000 instead. Exponent notation, commas and internal spaces are rejected; 1_000_000 is accepted.
Is my input sent to a server?
No. Computation runs in a browser worker. DevToolsy does not upload or store your input.
What does Copy include?
Copy exports the selected displayed value. Download JSON preserves strings and diagnostic codes; it does not turn large numbers into floating-point values.