Okta
okta.com › identity-101 › password-entropy
Password Entropy: The Value of Unpredictable Passwords | Okta
Password entropy is a measurement of how unpredictable, and therefore un-guessable, a password is.
Proton
proton.me › blog › what-is-password-entropy
What is password entropy? | Proton
October 5, 2023 - Of all the elements listed here, password length is the most important. A long enough passphrase will defeat almost any brute force attack. And you can increase entropy further by using random uppercase letters, special symbols, and numerals.
Videos
How much entropy does my password have?
To find out how much entropy a password contains, follow these steps:
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Determine the length of your password — how many characters there are.
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Calculate the size of the pool of symbols from which you've taken the characters. For instance, if you only use lowercase letters, the pool size is 26. If you additionally use some digits, the pool size is already 36.
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Compute the entropy as password its length times the log of the pool size to base 2.
omnicalculator.com
omnicalculator.com › other › password-entropy
Password Entropy Calculator
How many bits of entropy for a good password?
For non-vital accounts, 25-30 bits of entropy are enough. For more important accounts, aim for 60-80 bits of entropy, up to 100 for crucial ones.
omnicalculator.com
omnicalculator.com › other › password-entropy
Password Entropy Calculator
How to calculate password strength?
Password strength is quantified by password entropy, which is the log of the number of trials an adversary would have to make in order to guess your password.
omnicalculator.com
omnicalculator.com › other › password-entropy
Password Entropy Calculator
measure of the effectiveness of a password in resisting guessing and brute-force attacks
Wikipedia
en.wikipedia.org › wiki › Password_strength
Password strength - Wikipedia
1 day ago - To find the length, L, needed to achieve a desired strength H, with a password drawn randomly from a set of N symbols, one computes: ... {\displaystyle \left\lceil \ \right\rceil } denotes the mathematical ceiling function, i.e. rounding up to the next largest whole number. People are notoriously poor at achieving sufficient entropy to produce satisfactory passwords.
Omni Calculator
omnicalculator.com › other › password-entropy
Password Entropy Calculator
March 20, 2024 - This password entropy calculator can compute how strong your password is.
Passbolt
passbolt.com › blog › show-me-your-entropy-and-ill-break-your-password
Show me your entropy and I’ll break your password
July 29, 2024 - We know the password therefore there is no information to recover and the entropy is null!" Wow, you read the first article right? That's a real pleasure to see. But, let's pretend we don't know it just for the example please. ... On the chart, we see 4 curves, the straight ones are the evolution of entropy given a mask size and different password lengths.
Alecmccutcheon
alecmccutcheon.github.io › Password-Entropy-Calculator
Password Entropy Calculator
Primarily this relies on letter trigraphs, which check each set of 3 characters in a given password. This also calculates the entropy bits based on Claude Shannon's technique on determining the number of bits required to represent a set of characters and multiplying it by the length of the password.
SpecopsSoft
specopssoft.com › home › blog › news and research › all about password entropy
Understanding Password Entropy
May 3, 2021 - In the example above with L = 10 and R = 62, entropy comes out to ≈ 60. In Specops Password Auditor, we visualize this calculation with bar graphs.
Pleacher
pleacher.com › mp › mlessons › algebra › entropy.html
Password Entropy
Password entropy is a measurement of how unpredictable a password is. The formula for entropy is: E stands for "entropy," which is the opposite of an ordered pattern. Entropy is good: the bigger the E, the harder a password is to crack · We calculate password entropy by first looking at the ...
Dev Lateral
devlateral.com › home › tools › password entropy calculator
Password Entropy Calculator Tool | Dev Lateral
Find out how strong your passwords are with our free to use password entropy calculator. Strong entropy bits means more secure passwords.
NordVPN
nordvpn.com › blog › what-is-password-entropy
Password entropy and how to calculate it | NordVPN
September 2, 2025 - The best way to protect your account is to use a long and intricate password that takes ages to crack. The number of attempts an attacker would need to guess your password is a good measure of password strength, and this measure is known as password entropy.
Baeldung
baeldung.com › home › security › how to determine the entropy of a password?
How to Determine the Entropy of a Password? | Baeldung on Computer Science
March 18, 2024 - Now let’s take an example password and calculate the entropy score. Specifically, we’re taking a 10-digit long password that contains uppercase, lowercase, and numbers: Better2023. Here, the password length L = 10. As the password contains uppercase, lowercase, and numbers, the rage of the characters R = 26 + 26 + 10 = 62.
TechTarget
techtarget.com › whatis › definition › password-entropy
What is password entropy? | Definition from TechTarget
In this case, however, the password contains only lowercase letters, so there is only one set of 26 characters, which means that there are only 26 possible characters. Therefore, the R value in the equation is 26, and the L value is 9 to reflect the password's length. ... You can now plug these figures into the entropy formula and calculate the total entropy.
Password Generator
generatepasswords.org › how-to-calculate-entropy
How to Calculate Password Entropy? - Password Generator
June 10, 2019 - Expected Number of guesses (to have a 50% chance of guessing the password) = 2Entropy-1 · The following table illustrates some examples of entropy calculations of passwords of varying strength:
Timcutting
timcutting.co.uk › tools › password-entropy
Password Entropy Calculator by Tim Cutting
Tim Cutting is a frontend web developer and UI designer. Based in Colchester, UK, he primarily works in JS, React, Wordpress.
PlanetScale
planetscale.com › blog › using-entropy-for-user-friendly-strong-passwords
Using entropy for user-friendly strong passwords — PlanetScale
We wrapped our existing password form with auto-check-element. This web component posts the value of the password to our backend as the user types. Our backend then calculates the password’s entropy and returns the rendered meter SVG to show the user their progress.
Rumkin
rumkin.com › tools › password › passchk.php
Strength Test
People wonder if their password is a good password. I often come across two distinct groups of people. The first would fall into a "just use any word" category, which is a very bad practice for picking passwords. The second group will mix in a few numbers in order to make the password a lot ...
Weberblog
weberblog.net › password-strengthentropy-characters-vs-words
Password Strength/Entropy: Characters vs. Words | Weberblog.net
Then I calculated the entropy in bits while I rounded down the bit values. So, here comes the main graph: The x-axis shows the number of characters (password) respectively the number of words (passphrase) for the random chosen passwords/passphrases, while the y-axis shows the bits of entropy which the password/passphrase actually has.
ResearchGate
researchgate.net › figure › Password-strength-calculated-as-entropy-and-length-The-latter-which-was-initially_fig2_333645613
Password strength calculated as entropy and length. The latter, which... | Download Scientific Diagram
Download scientific diagram | Password strength calculated as entropy and length. The latter, which was initially measured in characters, was converted to bits (8 bits per character) for visualization purposes. Password meters resulted in the highest score of entropy and length.
Reddit
reddit.com › r/cybersecurity › using entropy as a measure of password strength
r/cybersecurity on Reddit: Using entropy as a measure of password strength
August 6, 2025 -
I am currently helping in reviewing the company's password policy and looking at the shopping list of mandatory characteristics for building strong passwords, I got to thinking:
Why is it a standard practice to do qualitative rating of passwords based on it having a whole bunch of different criteria met instead of using a more quantitative rating based on it's entropy?
I get that one is easier for the user to achieve than the other, but a password manager can easily calculate the entropy of the passwords it stores (though few actually do so).
I have even seen recommendations for using mnemonics to remember passwords where the mnemonic would make for a stronger password than the actual password that it serves to remember. But since it doesn't have funky characters it doesn't pass muster.
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Because you cannot accurately measure entropy based on a single password. A proper estimate of entropy is based on examining the app that generated the password. Since the workflow is limited to inspecting the drain bamaged suggestions that users are suggesting for a password, we are left in a difficult position. These “entropy calculators” that examine a single password are snake oil, but too many users try to use their sad little brains instead of a PRNG and a reputable password/passphrase app.
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I'm in the identity space and this is a pretty common library to use: https://github.com/dropbox/zxcvbn Instead of a policy like LUDS (lowercase, uppercase, decimal, symbol), using a library like zxcvbn and enforcing a strong password is a far better choice.
Redkestrel
redkestrel.co.uk › articles › random-password-strength
Random Password Strength
The table below gives the entropy per character for a number of different sized character pools. So, from the table above, we can see that a 20 character password chosen at random from the keyboard's set of 94 printable characters would have more than 128 bits (6.55 * 20) of entropy.