NOT Hex Numbers
Calculate bitwise NOT of hexadecimal numbers (each inverted within its own bit-width). Runs entirely in your browser, so your data never leaves your device.
0 chars · 0 lines
Output
The result appears here as you type.
How to use NOT Hex Numbers
- 1. List the values to invert. Paste one or more hex numbers into the input pane, each on its own line or separated by spaces. Every value is processed independently rather than combined with its neighbors.
- 2. Note the per-value bit-width. There is nothing to configure: each number is inverted within its own width, determined by its digit count. So ff maps to 0, while 00ff would map to ff00, because the extra digits widen the field.
- 3. Copy the inverted list. The output pane lists the NOT of every input in the same order. Copy the whole column back into your header file or test vectors in one motion.
When to use NOT Hex Numbers
NOT Hex Numbers flips every bit of each value you give it, treating each number's own digit count as its bit-width. It is effectively a batch complement calculator, ideal when a whole column of masks or constants needs inverting at once instead of one value at a time.
- Inverting a table of bitmasks. A driver header defines a dozen enable masks and you need the matching disable masks for each. Paste all twelve, copy back all twelve complements, and keep the ordering intact.
- Illustrating width sensitivity in complements. Students often miss that NOT depends on operand width. Feeding f, 0f and 000f into this tool shows three different answers from the same numeric value, making the lesson concrete.
- Cross-checking a code review claim. A pull request swaps a hard-coded constant for the complement of another. Run the original through NOT at the same width to verify the two constants really are complements.
- Building ones' complement test data. When testing serialization of ones' complement fields, you need input and inverted output pairs at several widths. Generate the entire expectation column here in a single pass.
Examples
NOT a byte
Input
ff
Output
0
NOT each number
Input
f 0
Output
0 f
About the NOT Hex Numbers tool
NOT Hex Numbers runs as plain JavaScript in your browser tab, with no server behind it. Calculate bitwise NOT of hexadecimal numbers (each inverted within its own bit-width). Whatever you put in stays on your device from start to finish.
The tool is part of EditSafely's Hex Tools section, 108 single-purpose utilities built around the same idea: open the page, get the result, keep your data to yourself.
There is nothing to configure. Provide the input and the result appears on its own. 2 worked examples further down the page show exactly what the tool produces for real inputs.
That local-first design has practical benefits beyond privacy. The tool keeps working on a flaky connection once the page has loaded, results are instant because nothing round-trips to a server, and it is safe to use with confidential material.
Frequently asked questions
Is NOT Hex Numbers free to use?
Yes, it is completely free. All 2,658 tools on EditSafely work without an account, a subscription or usage limits.
Is it safe to paste sensitive or confidential data?
Everything happens locally. Your browser downloads the tool's code once, then does all the processing itself; nothing you enter is transmitted, stored or logged. You can even go offline after the page loads and it will still work.
How much text can I process at once?
There is no fixed limit. Because the work happens on your own device rather than on a shared server, the practical ceiling is your machine's memory, which comfortably handles inputs far larger than typical online tools allow.
Do I need to sign up or install anything?
No. The tool works in any modern browser on desktop, tablet or phone. There is no account to create, no extension to add and no software to install.
How do I use the result?
The output panel has a one-click copy button, and you can keep refining the input while you work; the result updates in place as you type.
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