Animated entropy bars, a real strength meter, and a genuinely private breach check

Metre2 Password Strength Studio

A visual password generator and strength meter with animated per-character entropy bars, crack-time estimates across four real attack scenarios, and an optional breach check against the free Have I Been Pwned "Pwned Passwords" database - using k-anonymity, so only a 5-character hash prefix ever leaves your device. Your actual password never does.

Metre2 Password Strength Studio Meter and Generator tab showing animated per-character entropy bars, a 5-segment strength meter, crack-time table, breach-check result and a generator panel

Animated per-character entropy bars

Every character in your password gets its own bar, coloured by class - lowercase, uppercase, digit or symbol - and sized by how much it contributes to your password's overall entropy. A genuinely different way to see a password than a plain progress bar.

A strength meter that isn't naive

Starts from Shannon-style entropy, then applies real penalties for common passwords, dictionary words (leetspeak-normalised), sequential runs, keyboard-walk patterns and repeated characters - so "P@ssw0rd1" doesn't score as strong as it looks.

Crack-time estimates, four scenarios

See roughly how long a password would survive against a throttled login form, an unthrottled API, an offline slow-hash crack, and an offline GPU farm - turning an abstract "bits of entropy" number into something concrete.

Optional breach check, real k-anonymity

Checks your password against the free Have I Been Pwned "Pwned Passwords" database. Only the first 5 characters of your password's SHA-1 hash are ever sent - the match against your full hash happens locally, so your real password never leaves the device.

Character or passphrase generator

Generate a random character password (choose length, and which of lowercase/uppercase/digits/symbols to include, with an option to exclude ambiguous characters), or a word-based passphrase with your choice of separator and capitalisation.

Genuinely random, on-device

Generation uses the browser's cryptographically secure random number generator - not a simple pseudo-random function - so guaranteed-inclusion character sets and passphrase word picks are both properly unpredictable.

History without the risk

Every check is logged with its length, strength band, timestamp and breach result - but never the password itself, and never even a hash of it. A weak password's hash is itself reversible via rainbow tables, so storing it would defeat the entire point.

Pattern detection you can see

Sequential runs ("1234"), keyboard-walk runs ("qwerty"), repeated characters and repeated blocks are each flagged individually as tags, so you know exactly what's weakening a password - not just a single opaque score.

Light/dark theme

Switch between a light or dark theme that remembers your choice, so entropy bars and strength colours stay readable whatever the time of day.

Free, no account required

No sign-up, no subscription, no ads. Everything runs locally except the one opt-in breach-check request - and even that never carries anything identifying.

Not a password manager

This is a strength-checking and generation tool, not a vault - it deliberately doesn't store the passwords you check or generate, so there's nothing sensitive to protect, back up or lose.

How it compares to a browser's built-in password strength bar

Most people check password strength with a browser's basic colour-changing bar, or don't check it at all. Here's how a dedicated tool with a real breach check compares.

Feature Metre2 Password Strength Studio A browser's built-in strength bar An online password-strength website
Pricing model Free Free (built in) Usually free, ad-supported
Pattern-aware scoring (common passwords, dictionary words, keyboard walks) (usually length/character-class only) Varies
Breach check with k-anonymity (only a hash prefix is ever sent) Rare - and rarely disclosed clearly
Password ever leaves your device ✕ Never ✕ Never Sometimes, in full - a real risk with an unknown site
Built-in generator (character + passphrase) Varies
Crack-time estimates (4 attack scenarios) Rare

General comparison as of August 2026. Not affiliated with Have I Been Pwned, any browser vendor, or any third-party password-strength website.

Metre2 Password Strength Studio, in practice

Frequently asked questions

Does my password ever get sent anywhere?

No, never in full. The strength meter, entropy bars and generator all run entirely on your device. The optional breach check uses k-anonymity: only the first 5 characters of your password's SHA-1 hash are sent to the free Have I Been Pwned API - never the password itself, and never the full hash.

What is k-anonymity and why does it matter here?

Your password is hashed with SHA-1 locally, then only a 5-character prefix of that hash is sent to the Have I Been Pwned API. The API returns every breached hash suffix that starts with that prefix (usually hundreds), and the match against your full hash happens locally on your device. There's no way for the API, or anyone watching the request, to work out what your password actually is.

What are the entropy bars?

Each bar represents one character of your password, coloured by character class (lowercase, uppercase, digit, symbol) and sized by how much it contributes to your password's overall entropy. It's a quick visual way to see which parts of a password are doing the real work.

Is the strength meter just counting characters?

No. It starts from Shannon-style entropy based on character-pool size and length, then applies real penalties for patterns that make passwords easier to guess in practice - common passwords, dictionary words (including leetspeak substitutions), sequential runs like "1234" or "abcd", keyboard-walk runs like "qwerty", and repeated characters or blocks.

What do the crack-time estimates mean?

They show roughly how long a password would take to guess under four different attack scenarios: a throttled online login form, an unthrottled online API, an offline slow-hash crack, and an offline GPU cracking farm. It's a rough guide, not a guarantee - but it makes an abstract entropy number concrete.

Does it store my passwords anywhere?

No. History only ever stores metadata - length, strength band, timestamp and breach result - never the password itself, and never even a hash of it (a weak password's hash is itself reversible via rainbow tables, so storing it would defeat the point).

Ready to see what your password is really made of?