Password Generator

Generate strong, random passwords from 8 to 64 characters. Choose letters, numbers and symbols, avoid look-alike characters, and copy with one click. Nothing is sent or stored.

Security ToolsProcessed locallyNo account needed

Very strongabout 127 bits

Made with your browser's secure random generator. Passwords are never sent or saved.

How to use Password Generator

Simple steps to get your task done in seconds

Pick a length

Use 16 characters or more for important accounts.

Choose characters

Mix uppercase, lowercase, numbers and symbols. Avoid look-alikes for passwords you type by hand.

Copy

Copy one of the generated passwords into your password manager.

How Cryptographically Secure Password Generation Works

ZapPebble generates unguessable, high-entropy passwords using your browser's native CSPRNG (Cryptographically Secure Pseudorandom Number Generator) via window.crypto.getRandomValues(). Unlike insecure generators that rely on pseudo-random functions like Math.random() (which are vulnerable to algorithmic prediction), ZapPebble uses hardware entropy sources and unbiased rejection sampling to ensure every character has an equal, unbiased mathematical probability of selection.

Security Property	Implementation Value	Cryptographic Verification
Randomness Engine	window.crypto.getRandomValues()	Native OS entropy source (kernel /dev/urandom or Windows CryptGenRandom).
Modulo Bias Prevention	Unbiased Rejection Sampling	Discards out-of-range integer values to guarantee uniform character distribution.
Shuffle Algorithm	Fisher-Yates Modern Shuffle	Guarantees chosen characters are distributed across unpredictable string positions.
Ambiguity Filter	Avoid Ambiguous Characters	Removes lookalikes (0, O, o, 1, l, I, \|) to prevent transcription errors.

Understanding Password Entropy (Strength in Bits)

The Math Behind Entropy

Entropy measures how many brute-force guesses an attacker would have to compute to guess your password. It is calculated as: Entropy = Length × log2(Pool Size).

Uppercase + Lowercase + Numbers + Symbols: 94 characters pool.
20 characters at 94 pool: ~131 bits of true entropy.
131 bits: Requires billions of years to crack with supercomputer clusters.

Recommended Usage By Account Tier

12–14 Characters: Casual forum logins, newsletters, and throwaway accounts.
16–20 Characters: Corporate email, social media profiles, and cloud storage.
24+ Characters: Password manager master passwords, crypto wallets, and root servers.

Zero Storage & Privacy Architecture

Zero Logging

Generated passwords exist only in volatile React component state in RAM. Once you copy your password or refresh the page, the string is erased from memory with zero trace.

100% Offline Capability

You can disconnect from the internet, turn on Airplane Mode, and generate passwords safely. No external web services or APIs are contacted.

Direct Clipboard Copy

Click the Copy button to transfer any password directly into your system clipboard, ready to paste into 1Password, Bitwarden, or Apple Keychain.

Protect PDFUse your newly generated password to lock confidential PDF files with AES-256 encryption.

URL Encoder & DecoderEncode API keys or authentication credentials safely for query strings.

JSON Formatter & ValidatorValidate and format configuration payloads and environment credentials.

Frequently Asked Questions

They use crypto.getRandomValues, the browser's cryptographically secure generator, with no bias between characters. At least one character from each type you select is included.

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