Why this tool is useful
Use the inspector when reviewing feature flags, capability masks, embedded registers or test fixtures and you need exact bit indexes rather than visual counting.
Developer & Data · runs locally
Bit Mask Inspector
Inspect an unsigned fixed-width mask as padded binary and list every set and clear bit position from least significant bit zero.
Ready. Your working data stays in this browser.
How it works
The browser validates the mask against the chosen width, scans every bit from position zero upward and reports popcount plus explicit set and clear position lists.
Practical example
The 8-bit mask 0xA5 equals binary 10100101, so positions 0, 2, 5 and 7 are set while positions 1, 3, 4 and 6 are clear.
Validation
The calculation is deterministic and explains validation errors instead of silently changing invalid input.
Privacy boundary
Input and output remain in this tab. Copy and download happen through browser APIs without a server upload.
Result passport
Every run reports its tool mode, timestamp and input/output size so transformed data can be audited.