Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Password
CLTSg_uQglfIs13H
Length
16
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter length.
- 2Enter character set.
- 3Enter reroll (any number).
- 4Read your password on the right — it updates as you type.
- 5Hit Share to keep the scenario or send it to someone.
About this calculator
Generates a random password. All randomness happens in your browser — nothing is sent anywhere.
Worked example
Using the values the calculator loads with:
Inputs
- Length: 16
- Character set: Letters + numbers + symbols
- Reroll (any number): 1
Results
- Password: cUnXd*!nnR1V@EvS
- Length: 16
What each field means
Inputs
- Length
- The length used in the calculation. Starts at 16 so you have a working example on load. Accepted range: 4–128.
- Character set
- Pick the option that matches your situation — the maths changes per option. Choices: Letters + numbers, Letters + numbers + symbols, Letters only, Numbers only.
- Reroll (any number)
- The reroll (any number) used in the calculation. Starts at 1 so you have a working example on load.
Results
- Password
- Returned as a plain value and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Length
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the password generator work?
Generates a random password. All randomness happens in your browser — nothing is sent anywhere.
What do I need to enter?
3 values: length, character set, and reroll (any number). Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the password result mean?
It is returned as a plain value and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Estimates assume standard, average conditions — local rules, pricing, and materials vary.
Who is this tool for?
It's built for anyone doing everyday planning maths — a quick estimate that would otherwise need four browser tabs and a calculator app.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Password Generator. Retrieved from https://www.revenuelab.fyi/toolbox/password-generator
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/password-generator" target="_blank" rel="noopener">Password Generator — RevenueLab</a> (2026).</p>
Source: [Password Generator — RevenueLab](https://www.revenuelab.fyi/toolbox/password-generator) (2026).