Input
Preparing your workspace…
How to use
- Paste binary digits with optional whitespace separators.
- Check the decoded text or the byte/UTF-8 error.
- Copy the text, including its original spaces and line breaks.
Reconstructing text from binary bytes
A binary text dump describes encoded bytes. Grouping the digits into eight-bit values reconstructs the byte stream; a UTF-8 decoder then reconstructs the original text.
This tool decodes text bytes rather than converting a whole binary number into decimal. A complete UTF-8 sequence is required for every non-ASCII character.
Representations and workflow
Whitespace between binary digits is ignored, but the total number of bits must be divisible by eight. Input such as 01000001 decodes to A.
01001000 01101001HiTwo eight-bit groups reconstruct the UTF-8 bytes for H and i.
Precision and validation
The decoder is strict: invalid continuation bytes, overlong encodings and unfinished multibyte characters produce an error. Invalid data is not replaced with a guessed character.
Interpreting and reusing the result
Control bytes remain actual controls in the copied result. A UTF-8 byte-order mark is preserved as U+FEFF rather than silently discarded. The workspace does not execute decoded markup.
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
Can I paste binary without spaces?
Yes. Continuous binary digits or digits separated by whitespace are accepted, provided the total forms whole bytes.
Why do valid eight-bit groups still give an error?
Whole bytes are not always valid UTF-8. A byte above 127 may need specific preceding or following bytes.
Does this support UTF-16 or legacy encodings?
No. The decoder uses UTF-8 only. Selecting an arbitrary legacy encoding would change the interpretation of the bytes.
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.