Guides
How to create a strong password on iPhone
Create a genuinely strong password or passphrase on iPhone using cryptographically secure randomness and an entropy target — on-device, free, and without paying a weekly subscription for a one-line OS feature.
Last updated June 22, 2026
Direct answer
A strong password is an unpredictable one — measured in bits of entropy, not in how many symbols it has. Pick a passphrase for accounts you type by hand or a long random string for ones your manager fills, generate it from a cryptographically secure source, aim for 60+ bits (77+ for banking and email), store it in a password manager, and never reuse it.
Strength is entropy, not “complexity rules”
Most password advice fixates on the wrong thing: one uppercase letter, one number, one symbol. That checklist produces predictable passwords like P@ssw0rd! that attackers crack in seconds, because the substitutions are exactly the ones everyone makes. What actually matters is entropy — how many equally likely possibilities your password could have been, measured in bits. Each extra bit doubles the attacker’s work.
Two things raise entropy: length and genuine randomness. A 16-character string drawn randomly from a full character set, or a passphrase of 6 random words, reaches high entropy while a clever-looking 8-character password does not. NIST’s modern guidance reflects this — it tells sites to allow long passphrases, stop forcing arbitrary symbol rules, and stop forcing periodic resets.
Pick the right kind for the account
For accounts you log into by hand — your laptop login, your password-manager master password, work SSO — use a passphrase: several random words you can actually remember. Six random words is memorable and reaches the entropy of a strong random password.
For accounts your password manager fills for you — most websites — use a long random string. You will never type it, so memorability does not matter; just maximize length and randomness.
Generate it the right way
The source of randomness matters as much as the length. A safe generator draws from a cryptographically secure source — iOS SecRandomCopyBytes on-device, or the browser’s Web Crypto API on the web. An unsafe one uses Math.random, which is predictable and must never be used for passwords.
You can generate one right now in the browser with the free password generator tool — it shows the exact entropy in bits and runs entirely on your device, nothing uploaded. On iPhone, Password Generator does the same on-device with full Diceware passphrases, per-site rule presets, an entropy meter, and an auto-clear clipboard.
Steps
- Decide passphrase (typed by hand) or random string (manager-filled).
- Set an entropy target: 60+ bits everyday, 70+ for email/social, 80+ for banking and master passwords.
- Generate it from a cryptographically secure source — never
Math.random. - Store it in a password manager immediately, never on paper.
- Use a unique password for every account.
Don’t pay weekly for a one-line feature
Generating a password is a single operating-system call with no infrastructure behind it, which is why The Washington Post, 9to5Mac, and Sophos have all flagged App Store password generators charging $19.99 per week as some of the most extreme fleeceware on the platform. The weekly billing is the trap, not the price. Swarmval Password Generator ships with the studio’s standard fair pricing — a useful free tier, then $4.99/month with a 3-day trial, $14.99/year, or $19.99 once for lifetime. Never weekly.
Common questions
What actually makes a password strong? +
Unpredictability, measured in bits of entropy — not whether it has a capital letter and a symbol. A truly random 16-character password or a 6-word passphrase has far more entropy than 'P@ssw0rd!' even though the latter satisfies every 'complexity rule.' Length and randomness beat forced symbols. Aim for 60+ bits for ordinary accounts and 77+ bits for banking, email, and your password-manager master password.
Is iCloud Keychain enough? +
For everyday Safari logins, yes — iCloud Keychain generates strong random passwords, stores them, and fills them, all free. Where a dedicated generator helps is memorable passphrases (for accounts you type by hand), per-site rule presets for sites that reject certain symbols, an explicit entropy meter, and length control. Use Keychain as your store; use a generator when you need control.
Should I use a passphrase or a random string? +
Use whichever you can remember without writing it down. Accounts you type by hand — laptop login, password-manager master, work SSO — are best as a multi-word passphrase, which reaches high entropy while staying memorable. Accounts you only open through a password manager can use a long random string, because you will never type it.
Why do some iPhone password apps cost $19.99 a week? +
Generating a password is a single operating-system call with no server cost, yet this category was named by The Washington Post, 9to5Mac, and Sophos as one of the App Store's worst 'fleeceware' categories for billing $19.99 per week. The weekly billing is the trap. Swarmval Password Generator ships at fair pricing: a free tier, $4.99/month with a 3-day trial, $14.99/year, or $19.99 once for lifetime — never weekly.
Do I need to change strong passwords every few months? +
No. Current NIST guidance says forced periodic changes make security worse, because people just increment a number or pick something weaker. Change a password only when you have a reason: a known breach, a shared device, or a password you suspect was seen. A strong, unique password per account plus a password manager beats routine rotation.
Steps
-
Step 1
Decide passphrase or random string
For accounts you type by hand (laptop, password-manager master, work SSO), choose a multi-word passphrase you can memorize. For accounts your password manager fills, choose a long random string you will never type.
-
Step 2
Set an entropy target
Aim for 60+ bits for everyday accounts, 70+ for email and social, and 80+ for banking and master passwords. That is roughly 12, 16, and 20 random characters — or 5, 6, and 7 words.
-
Step 3
Generate it with secure randomness
Use a generator that draws from a cryptographically secure source (iOS SecRandomCopyBytes or the browser's Web Crypto API), never Math.random. Swarmval Password Generator does this on-device; the free in-browser tool does it in your browser.
-
Step 4
Store it in a password manager
Save the new password in iCloud Keychain, 1Password, or Bitwarden immediately — never on paper or in Notes. A generator's job ends when the password exists; the manager remembers and fills it.
-
Step 5
Use a unique password per account
Never reuse a password across sites. Reuse is what turns one site's breach into a takeover of your email and bank. One strong, unique password per account is the single highest-impact habit.
Frequently asked questions
What actually makes a password strong?
Unpredictability, measured in bits of entropy — not whether it has a capital letter and a symbol. A truly random 16-character password or a 6-word passphrase has far more entropy than 'P@ssw0rd!' even though the latter satisfies every 'complexity rule.' Length and randomness beat forced symbols. Aim for 60+ bits for ordinary accounts and 77+ bits for banking, email, and your password-manager master password.
Is iCloud Keychain enough?
For everyday Safari logins, yes — iCloud Keychain generates strong random passwords, stores them, and fills them, all free. Where a dedicated generator helps is memorable passphrases (for accounts you type by hand), per-site rule presets for sites that reject certain symbols, an explicit entropy meter, and length control. Use Keychain as your store; use a generator when you need control.
Should I use a passphrase or a random string?
Use whichever you can remember without writing it down. Accounts you type by hand — laptop login, password-manager master, work SSO — are best as a multi-word passphrase, which reaches high entropy while staying memorable. Accounts you only open through a password manager can use a long random string, because you will never type it.
Why do some iPhone password apps cost $19.99 a week?
Generating a password is a single operating-system call with no server cost, yet this category was named by The Washington Post, 9to5Mac, and Sophos as one of the App Store's worst 'fleeceware' categories for billing $19.99 per week. The weekly billing is the trap. Swarmval Password Generator ships at fair pricing: a free tier, $4.99/month with a 3-day trial, $14.99/year, or $19.99 once for lifetime — never weekly.
Do I need to change strong passwords every few months?
No. Current NIST guidance says forced periodic changes make security worse, because people just increment a number or pick something weaker. Change a password only when you have a reason: a known breach, a shared device, or a password you suspect was seen. A strong, unique password per account plus a password manager beats routine rotation.