How to Generate a Strong Password That Never Leaves Your Device

A site demands a "strong" password to open a new account, so you open the first password generator site that shows up in search results and copy whatever it displays. You have no idea who built that site, where the password it generated for you was processed, or whether it passed through their server before landing on your screen. The irony is that a tool meant to protect you can end up being the weak point itself.

Why does it matter where a password is generated?

A password generator that works by sending a request to a remote server to build the password and then returns it to you over the internet means that password traveled through a network and a server you do not control, and if those requests were logged in any way — even with no ill intent from the site owner — your password became known to an outside party before you ever used it. The password generator on Sahel creates the password entirely inside your browser, from your own devices randomness source, with no connection to a server to generate it.

How is password strength actually measured?

A vague label like "strong" or "medium" tells you nothing precise. The correct measurement is bits of entropy, representing the number of random guesses someone trying to crack the password would need before hitting it. Every extra character from a wider character pool — uppercase, lowercase, digits, and symbols — adds more bits than the same extra length from a narrow pool like digits alone. Sahels tool shows password strength in bits directly, so you can compare two options clearly instead of relying on a colored bar or a vague descriptive word.

Length matters more than complexity sometimes

A relatively long password with simple characters can actually be stronger than a short, complex one packed with symbols, because the total number of possibilities scales exponentially with length. That means adding a few more characters to a passwords length is usually better than adding one special symbol to a short one, even though the symbol looks "stronger" visually.

Steps to generate a password

1. Set the length you need — longer is stronger, within whatever limit the site you will use it on accepts.
2. Choose the character types: uppercase, lowercase, digits, and special symbols.
3. Turn on the option to avoid look-alike characters (like the digit zero and the letter O) if you will be typing it by hand elsewhere.
4. Check the strength in bits before copying.
5. Copy the password and save it immediately in a trusted password manager instead of leaving it in the clipboard.

Why avoid look-alike characters sometimes?

If you will be typing the password by hand — on another device, or dictating it to someone over the phone — the similarity between the digit one and a lowercase L, or zero and a capital O, causes repeated, frustrating entry errors. Disabling these characters slightly reduces the possible combinations, and so slightly reduces the strength in bits, but it is worth it for cases of repeated manual entry.

A real case

An IT staffer sets up accounts on ten different systems for a new hire in a single day, and needs a strong, unique temporary password for each system to hand over for the employee to change later themselves. He opens the generator ten times, adjusting the length and character types to fit each systems requirements — some older systems reject certain special symbols — and copies each password straight to its correct place the moment it is generated, instead of saving them all in an unsecured text file on the desktop.

In another case, someone resets their email password after being alerted to a security breach at another site where they had reused the same old password. They generate a new, strong, unique password and use it for that one account only, without repeating it anywhere else.

Frequently asked

Is the generated password sent to any server?

No, generation happens entirely inside your browser using your own devices randomness source, and the password never leaves your device at any stage of its creation.

What length is right for a strong password?

Strength grows significantly with length, and the general practical rule is to choose the longest password the site or system you are using accepts, not the shortest one that just clears the minimum requirement.

Do I need to memorize a generated password?

No need to keep it in memory; it is better to use a trusted password manager that stores it encrypted rather than trying to manually memorize long random strings, and that is the whole point of using a strong random password in the first place.

Is it safe to reuse the same strong password across several accounts?

No, a passwords strength alone does not protect against a completely different risk: if it leaks from a breach at one site, it will be tried against all your other accounts too. A unique password per account matters more than the strength of any single password in this scenario.

Are special symbols mandatory for a strong password?

Not always; a long password using only letters and digits can be stronger than a short one packed with symbols, though mixing character types generally increases strength for the same length.

Try the tool

Open the password generator, set the length and character types, and get a strong password created only on your device.