How to Generate a Strong Random Password Online

To generate a strong password, use a browser-based generator that draws from cryptographically secure randomness — set the length to at least 12–16 characters, mix uppercase, lowercase, digits and symbols, and copy the result. Because the password is created on your device and never sent anywhere, only you ever see it.

This guide covers how to pick a length, what the entropy meter is telling you, and why a browser generator is safer than one that builds passwords on a server.

Why strong, unique passwords matter

The biggest real-world threat is not brute-forcing a single account but credential stuffing — attackers reusing passwords leaked from one breach across every other site. A long, random, unique-per-site password defeats that entirely, because a leak from one service reveals nothing about the others. Predictable passwords built from names, dates or common words fall in seconds; genuine randomness is what makes them hard to guess.

How to generate a password in your browser

1. Set the length with the slider — 12 to 20 characters is a strong default for most accounts.
2. Tick the character sets to include: lowercase, uppercase, digits and symbols.
3. Optionally exclude ambiguous characters like 0/O and 1/l/I for easier reading.
4. Click Generate, check the entropy strength meter, and copy the password.
5. Need several at once? Set a count and generate a whole batch to copy individually.

How length and character sets affect strength

Entropy, measured in bits, is the true measure of password strength — each extra bit doubles the guesses an attacker needs. This table shows roughly what different choices deliver:

Length	Character pool	Approx. entropy
8	Letters + digits (62)	~48 bits (weak)
12	All sets (94)	~78 bits (strong)
16	All sets (94)	~105 bits (excellent)
20+	All sets (94)	~130+ bits (overkill, ideal for master keys)

Entropy is calculated as length × log2(pool size), so adding length or another character set both help — and length usually wins.

Key features

• Cryptographically secure randomness via crypto.getRandomValues.
• Length from 4 to 128 characters.
• Lowercase, uppercase, digits and symbols toggles.
• Exclude ambiguous characters option (0 O 1 l I).
• Entropy-based strength meter in bits.
• Generate multiple passwords and copy with one click — all offline and private.

Try the Password Generator now — it's free and runs entirely in your browser.

Frequently asked questions

Are random password generators safe to use?

A browser-based generator like this one is safe because it runs entirely on your device with the Web Crypto API — the password is never transmitted or stored. Avoid generators that create passwords on a server, since you cannot verify what happens to them.

How long should a strong password be?

Aim for at least 12–16 characters with mixed sets, giving roughly 78–104 bits of entropy — far beyond practical brute force. For master passwords and encryption keys, 20+ characters adds a comfortable margin.

What does the entropy strength meter mean?

Entropy is unpredictability in bits, and each extra bit doubles the attacker's work. A 16-character password from a 94-character pool is about 105 bits — effectively uncrackable with today's hardware.

Why exclude ambiguous characters like 0 and O?

In many fonts 0/O and 1/l/I look identical, causing errors when a password is read from paper, dictated, or typed on a TV keyboard. Excluding them trims entropy slightly, so add a character or two of length to compensate.

Should I use a password manager too?

Yes. Generate a unique password here, then store it in a reputable password manager rather than reusing it. Unique-per-site passwords are the strongest defence against credential-stuffing attacks.

Related free tools

• UUID Generator — create random unique identifiers.
• Random Number Generator — generate secure random numbers.
• SHA-256 Hash Generator — hash text and passwords locally.
• Random Name Generator — generate random names and handles.

Built by ByteVancer

ByteTools is a free product of ByteVancer, a software and web development studio that builds web apps, SaaS platforms and custom software for businesses. If your product needs secure authentication or custom security tooling, explore ByteVancer's services or reach out to start a project.