Count Number of Ones
Quickly find the number of high bits in binary values. Runs entirely in your browser, so your data never leaves your device.
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Output
The result appears here as you type.
How to use Count Number of Ones
- 1. Paste your binary values. Enter one or more binary numbers into the input pane, such as bitmask values from a register you want to audit for enabled flags.
- 2. Read the ones count. The tool sums the high bits across your input, giving you the Hamming weight, the total count of 1s regardless of how the value is grouped.
- 3. Copy the count. Copy the resulting number from the output pane into a code comment, a bitmask audit spreadsheet, or a coding interview practice log.
When to use Count Number of Ones
Count Number of Ones reports the Hamming weight of one or more binary values, the total count of set bits. It is aimed at anyone auditing bitmasks, studying popcount algorithms, or just checking how many flags are turned on.
- Auditing a permissions or feature-flag bitmask. A configuration system packs dozens of feature flags into one binary value and you want a quick sanity check on how many are currently enabled.
- Practicing a popcount coding interview question. You are studying bit manipulation problems and want to verify the expected Hamming weight of a test value before writing your own popcount function.
- Checking error correction or parity logic. You are working through a Hamming code exercise and need the exact count of set bits in a codeword to verify a parity calculation.
Examples
Count ones
Input
1010 1100
Output
4
Count ones in one value
Input
1111
Output
4
About the Count Number of Ones tool
Count Number of Ones is a free online tool that works entirely inside your web browser. Quickly find the number of high bits in binary values. Because the processing happens on your own device, nothing you enter is uploaded, logged or stored anywhere.
This page is one of 112 Binary utilities on EditSafely. Each one does a single job well, and all of them follow the same rule: your input stays on your machine.
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.
Because nothing leaves your device, the tool is suitable for sensitive content such as internal documents, credentials or customer data. It also responds instantly, since every keystroke is handled on your own machine rather than by a remote API.
Frequently asked questions
Does Count Number of Ones cost anything?
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?
No data leaves your device. The whole tool is JavaScript that runs inside your browser tab, so there is no upload, no server-side processing and no log of what you did. If you disconnect from the internet after the page loads, it keeps working.
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?
Nothing to install and no account needed. Open the page in any up-to-date browser, including on a phone or tablet, and the tool is ready.
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.