What is Password Generator?
Most data breaches occur due to reused or weak passwords. Generating a password locally using cryptographically secure random number generators (CSPRNG) ensures that not only is the password virtually impossible to brute-force, but its creation is completely invisible to the internet. This tool leverages the Web Crypto API to guarantee true randomness, avoiding the predictable patterns of pseudo-random generators (like Math.random).
Before you use this tool
Start with a small, representative example and check the result before you rely on it in a larger workflow. Keep the original data and look closely at the edge cases. The safest tool is the one whose limits you understand.
Deep Dive: Password Generator
Related Articles
Learn more about this tool and related topics in our blog.
The Developer's Guide to Passwords and Entropy in 2026
A practical look at password security, entropy, and safer ways to store passwords on the web.
How to Process Files Privately Without Uploading Them
Your files stay on your device. This guide explains how Filemint processes them in the browser instead of sending them to a server.
“The safest password is one that remains locally on your machine. By generating with the browser's secure random source and refusing to upload anything, we remove the server as a point of failure. Pair that with length over forced complexity and a password manager, and you have covered the two attacks that actually happen: guessing and credential reuse.”
Azeem Mustafa
Privacy Architect
Core Capabilities
- Cryptographically secure randomness (Web Crypto API)
- Real-time strength meter and entropy calculation
- One-click copy to clipboard
- Bulk generation (up to 100 at once)
- Custom character sets (Symbols, Numbers, Ambiguous chars)
- fully offline-capable-ready and private
Why It Matters
- Security: Generate passwords with stronger randomness than human-made patterns.
- Privacy: Passwords are created locally and never uploaded.
- Speed: Make a new password in seconds instead of inventing one from scratch.
- Flexibility: Match site-specific password rules without manual tweaking.
Quick Start Guide
Pick your vibe: Use the toggles to decide what goes in. Symbols? Numbers? Uppercase? If a site is being picky about rules, this is where you fix it.
Size matters: Slide that bar! 12 characters is okay for like, a random forum, but 16 or 24 is where it starts getting invincibile. Don't be afraid to go big.
Instant updates: Notice how the password changes every time you move a slider? That's the generator working in real-time. No need to click "submit" a thousand times.
Copy and roll: Once you see one you like, hit the copy button. It's securely added to your clipboard so you can just paste it into your app and be done.
Bulk Mode: If you're setting up a bunch of accounts at once, switch to the bulk tab and generate like 50 at a time. It's super useful for developers.
Usage Examples
High-entropy random password (16 chars)
Scenario 01Full character set with length 16 gives about 105 bits of entropy, well past what brute force can reach.
Length: 16 Character set: a-z, A-Z, 0-9, symbols Mode: Random
kT9#mP2$vLq7@WxZ
Memorable passphrase (5 words)
Scenario 02Five random words joined by dashes reach roughly 64 bits and stay easy to say out loud.
Mode: Passphrase Words: 5 Separator: - Word list: 7776 entries
correct-horse-battery-staple
Ambiguous-free Wi-Fi key (20 chars)
Scenario 03Removing 0, O, 1, l, I makes the key safe to read aloud and type on a phone.
Length: 20 Avoid Ambiguous: on Character set: a-z, A-Z, 0-9
WmXZ8eKcYq2sVnHp3rTu
Bulk batch for a team (10 passwords)
Scenario 04One click produces ten distinct values, each from the same secure random source.
Bulk count: 10 Length: 14 Character set: full
Rq2@Lp9#Wx3KmT Vb7!Nc4&Zs8YhJ... (10 total)
Common Scenarios
Personal account sign-ups
Every new site wants a password. A unique 16-character string stops one breach from spreading to your other accounts.
Wi-Fi and router access
Home and office networks need a shared key that guests can type. Exclude ambiguous characters so nobody mixes up 0 and O.
Database and admin logins
Server credentials should be long and random. A 24-character string resists both online guessing and offline cracking if the hash leaks.
API keys and tokens
Services often ask for a secret to call their API. A random password makes a solid token that is hard to forge.
Disk and file encryption
Tools like BitLocker or VeraCrypt ask for a passphrase. A five word random passphrase is strong and still memorable.
Shared team credentials
A temporary shared login for a project needs a fresh value nobody has used before. Bulk mode covers the whole group.
Test and staging environments
Developers need throwaway passwords for test databases. Random values keep tests realistic without reusing production secrets.
Password manager master key
The one password you must remember is the manager's master. A long random passphrase balances strength and recall.
Questions?
Technical Architecture
Secure random source
Passwords are drawn with crypto.getRandomValues, the Web Crypto API's CSPRNG. It is seeded from the operating system's entropy and is suitable for secrets, unlike Math.random().
Entropy formula
Entropy in bits equals length times log2(pool size). A 12 character password from 94 symbols is 12 x 6.55, about 78 bits. Each added character multiplies the search space by the full pool.
Local-only processing
All generation runs in your browser tab. The page makes no network request carrying your password. You can open the developer tools network panel and watch: there is no upload.
No logging or storage
The tool keeps no server, no database, and no analytics tied to your output. The value lives in memory and is cleared when you navigate away or close the tab.
Passphrase math
A passphrase of W words from a list of S words carries W x log2(S) bits. Five words from a 7776 word list is about 64 bits. The strength comes from the random pick, not from the words themselves.
Standards we follow
We align with NIST SP 800-63B on length over forced complexity and with OWASP on how servers should store passwords (Argon2id, bcrypt, or PBKDF2 with a salt). Generation and storage are different jobs, and both matter.
How much entropy do you get per character set?
The table below shows how many bits each character adds, and the total for a 16 character password. Notice that adding symbols barely moves the number compared with simply making the password longer. This is the math behind NIST's advice to favor length.
Bits per character equal log2 of the pool size. Total is length times that value.
| Feature | Pool size | Bits / char | ★ Recommended16-char total |
|---|---|---|---|
| Digits only (0-9) | 10 | 3.32 | 53 bits |
| Lowercase (a-z) | 26 | 4.70 | 75 bits |
| Lower + upper + digits | 62 | 5.95 | 95 bits |
| Full printable ASCII | 94 | 6.55 | 105 bits |
| Bits added by one more char | - | - | +6.55 bits |
A 12 character password from the full set lands near 78 bits. That is the figure security writers cite as effectively uncrackable by brute force. Push to 16 characters and you clear 100 bits. You can read more about the storage side of this in our MD5 vs SHA-256 comparison.
Breaches are bigger than most people think
Have I Been Pwned holds billions of breached credentials, with one 2025 load alone adding roughly 1.3 billion unique passwords. When a password appears in a breach, attackers feed it into other sites through credential stuffing. A unique, random password is your best defense, and a password manager is how you keep track of many of them.
Known breached accounts (HIBP, Feb 2024)
Unique passwords in one 2025 breach load
Entropy of a 12-char random password
Sent to any server by this tool
The takeaway is simple. Use a different password per site, make each one long and random, and never let it leave your browser during creation. For PDFs that hold sensitive files, our Protect PDF tool adds encryption the same local way.
How long should your password be?
Follow the branch below. If the account is important or you cannot turn on two-factor authentication, go longer. If a system caps the length, fill it to the maximum it allows.
When you need a value that is not a login password, our UUID generator makes unique identifiers, and the hash generator turns data into a fixed fingerprint. For storing those hashes the right way, see password hash.
From idea to saved secret
The flow is short and stays on your device the whole time.
Choose settings
Length and set
Secure random
crypto API
Copy value
One click
Save locally
Your manager
Random vs passphrase at a glance
Both styles reach strong entropy when made at random. The chart compares entropy for a few common choices.
Bits of entropy for each option. Higher is harder to crack.
A four word passphrase sits near 51 bits, which is fine for low risk use. For sensitive accounts, lean on the 16 character random string or a six word phrase. The full picture on safe processing lives in our client-side processing privacy guide.
Where to learn more
These outside sources back the claims on this page. They are worth a read if you want the primary text rather than our summary.
- NIST SP 800-63B - the official password guidance on length, no forced changes, and breach screening.
- OWASP Password Storage Cheat Sheet - how servers should hash and salt passwords with Argon2id or bcrypt.
- Have I Been Pwned: Pwned Passwords - the breach corpus that shows why reuse is risky.
- Proton: What is password entropy? - a clear walk through the entropy formula.
- PCMag: How to Create a Strong Password - plain language advice for everyday users.
If you want the same privacy promise applied to your documents, start from the password generator and pair it with the file tools linked above.
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Learn more about this tool and related topics in our blog.
The Developer's Guide to Passwords and Entropy in 2026
A practical look at password security, entropy, and safer ways to store passwords on the web.
How to Process Files Privately Without Uploading Them
Your files stay on your device. This guide explains how Filemint processes them in the browser instead of sending them to a server.
Founder & Lead Developer at FileMint
Building privacy-first browser tools powered by WebAssembly. Focused on making file processing fast, secure, and accessible — without ever uploading your data to a server.
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