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Tools Calculators

Generators, checkers & specialty tools. All tools are free, instant, and updated for 2026.

About Tools calculators

A small set of utilities that do not compute a financial or physical quantity. Everything here runs entirely in your browser — nothing you type is transmitted, logged or stored.

That matters most for the password generator, where the security of the output depends on both the randomness source and where the work happens. It uses the operating system's cryptographic generator, not ordinary pseudo-randomness.

How to use these well

Everything runs in your browser
These tools do their work locally. Nothing you type is transmitted to a server for the calculation itself, which matters most for the generators and anything you paste in. It also means they keep working on a poor connection.
Randomness has grades
A password generator must use a cryptographically secure source of randomness. The ordinary random function built into a browser is fast and predictable enough to be unsuitable for anything protecting an account, even though the output looks the same to a human.
Length beats complexity
Each additional character multiplies the search space, while substituting symbols for letters adds far less than it appears to and is well modelled by cracking software. A long passphrase is stronger and easier to type than a short string of punctuation.
Entropy is the honest measure
Password strength is measured in bits of entropy, which describes how many guesses an attacker would need. It is the only measure that lets you compare two very different-looking passwords, and it depends on how the password was generated rather than how complicated it looks.
Generated output is not saved
Nothing generated here is stored or recoverable. If you generate something you need, capture it before leaving the page — usually into a password manager rather than a note.

Which one do you need?

You need a strong password
Password generator, which reports entropy in bits rather than a vague strength label.
You need to invoice a client
Invoice generator, which produces a PDF with no account required.
You are stuck on a word game
Word unscrambler, with filters for length, starting and ending letters.

Where these go wrong

  • Reusing a strong password

    Strength does not survive reuse. One breached site exposes every account sharing that password, which is why a manager and unique passwords beat memorising one good string.

  • Substituting symbols for letters

    Replacing a with @ and o with zero is the first thing cracking software tries. It adds almost nothing next to simply making the password longer.

  • Judging strength by how it looks

    A short string of punctuation looks stronger than a long passphrase and is usually far weaker. Bits of entropy is the measure that compares them honestly.

  • Leaving the page without saving the output

    Nothing generated here is stored or recoverable. Capture it into a password manager before navigating away.

Common questions

Is it safe to generate a password on a website?

It depends entirely on whether generation happens in your browser or on a server. This one runs locally using the operating system's cryptographic random generator and transmits nothing. A generator that sends the password to a server, or that uses ordinary pseudo-randomness, should not be trusted.

How long should a password be?

Sixteen characters of genuinely random text from a mixed pool gives around 100 bits of entropy, which is beyond brute force with any foreseeable hardware. Length matters far more than complexity — two extra characters beat adding an entire character class.

Do you store anything I enter?

No. These tools run client-side and nothing is sent to a server. Close the tab and the data is gone, which also means nothing is recoverable — save anything you need before you navigate away.

How long should a password be?

Longer than you think, and generated rather than invented. Length contributes more to strength than complexity does, and a manager removes the need to remember or type it, which removes the reason people keep them short.

Are the passwords generated here safe to use?

They are generated in your browser using the cryptographically secure randomness the browser provides, and nothing generated is transmitted or stored. Save it into a password manager before leaving the page, because it cannot be recovered afterwards.

What is entropy, in practical terms?

A count of how many guesses an attacker would need, expressed in bits. Each additional bit doubles the work. It is the only measure that lets you compare a long passphrase against a short jumble of symbols honestly.

Do these tools work offline?

Once the page has loaded, the calculations run locally, so a dropped connection does not stop them. Loading the page in the first place still requires a connection.