Bcrypt is a password hashing function designed to be computationally intensive and resistant to brute-force attacks. It incorporates a salt to protect against rainbow table attacks and a cost factor that lets you increase the hashing work over time as hardware gets faster. It is widely used for securely storing passwords in databases.

How many rounds (cost factor) should I use?

A cost factor of 12 is the recommended minimum for production environments as of current best practices. Higher values increase security but also increase processing time exponentially — each increment doubles the computation time. For most modern servers, 12 to 14 provides a good balance of security and performance.

Is this bcrypt generator secure to use?

Yes. All hashing and verification processing happens entirely within your browser using the bcryptjs JavaScript library. No data is transmitted to any server or stored anywhere. Your passwords and hashes never leave your device.

Can I use this tool in production?

This tool is primarily intended for testing, learning, and development purposes. For production applications, you should implement bcrypt hashing server-side using a trusted library in your programming language (e.g., bcrypt for Node.js, bcrypt for PHP, or Spring Security for Java) to ensure hashes are generated and compared securely within your own environment.

What is password hashing and why is it important?

Password hashing is a one-way cryptographic process that converts a plain text password into a fixed-length string called a hash. Because it is a one-way function, the original password cannot be derived from the hash. This means even if a database is breached, attackers cannot easily recover the actual passwords.

Why does bcrypt always produce a different hash for the same input?

Bcrypt automatically generates a unique random salt each time it hashes a string. This salt is embedded into the resulting hash string. Even if two users have the same password, their bcrypt hashes will be different, making precomputed rainbow table attacks ineffective.

How do I verify a bcrypt hash?

To verify a bcrypt hash, use the Verify Hash section: paste your existing bcrypt hash into the 'Bcrypt Hash' field and enter the original plain text password. The tool will compare them and tell you whether the text matches the hash. Bcrypt extracts the embedded salt from the hash to perform the comparison correctly.

What does the bcrypt hash string format look like?

A bcrypt hash looks like: $2a$12$N9qo8uLOickgx2ZMRZoMyeIjZAgcfl7p92ldGxad68LJZdL17lhWy. The prefix '$2a$' indicates the bcrypt algorithm version, '12' is the cost factor, the next 22 characters are the base64-encoded salt, and the remaining characters are the hashed password. The total length is always 60 characters.

Generate & Verify Bcrypt Hashes — Free Password Hashing Tool

In the Generate tab, enter a password and set the cost factor (4–14 salt rounds) to produce a ready-to-use bcrypt hash — the industry standard for secure password storage — plus a time estimate for your chosen cost level. Switch to the Verify tab, paste any password and existing bcrypt hash, and this free bcrypt generator instantly confirms whether they match.

Cost factor 10–12 is a reasonable range for most applications. Very high cost factors make every legitimate login noticeably slower too — benchmark on your own hardware before committing to a value in production.

Using the Bcrypt Hash Generator & Verifier to Generate Secure Password Hashes

This online bcrypt hasher makes it straightforward to produce a bcrypt hash from your text or any plaintext input.

To generate bcrypt password hashes, enter your password in the text field above, select your desired cost option using the rounds selector, then press the Bcrypt button. The tool immediately produces a bcrypted password — a 60-character string beginning with the $2b$ prefix — directly in your browser. Use it to generate password hashes with bcrypt algorithm for testing, storing passwords in databases, or validating your authentication flow.

Because this is a client-side bcrypt utility, all processing happens in your browser using the bcryptjs library. No data is sent to any servers, and no data stored anywhere — your credentials remain completely private. This browser-based processing model means you can safely use the tool even with sensitive test credentials, since data stays private throughout the entire session.

Understanding Your Bcrypt Hash Output

The hash produced by this bcrypt hash generator follows a well-defined structure. A typical output looks like this:

$2b$10$N9qo8uLOickgx2ZMRZoMyeIjZAgcfl7p92ldGxad68LJZdL17lhWy

Breaking this down: $2b$ identifies the bcrypt version; 10 is the cost factor (rounds); the next 22 characters are the base64-encoded random salt; and the remaining 31 characters are the hash itself. Because a cryptographically random salt is generated each time, the same plain text password will produce a completely different hash on every run — this is salted hashing working exactly as intended, and it is one of bcrypt's core strengths against rainbow table attack prevention.

Choosing Your Salt Rounds and Cost Factor

The rounds selector (also called the cost factor, or work factor) controls how computationally intensive the hashing process is, directly influencing the cpu cost factor applied during hash generation. The tool supports a range from 4 to 31, with a default of 10. Here is what each tier means in practice:

Rounds 4–8

Very fast — useful for automated tests. At these settings the tool uses minimal CPU power, ideal when writing tests that involve hashed credentials at scale.

Rounds 10 (default)

The recommended minimum for production use. Balances security and response time for most authentication workloads.

Rounds 12+

High security suitable for production environments handling sensitive financial or medical data. 12 rounds is widely cited as the floor for high-security contexts.

Rounds 14+

Each increment roughly doubles compute time. At very high values you risk denial of service and resource exhaustion attacks if an attacker can trigger mass hashing requests — cap rounds thoughtfully.

The key principle: more rounds increase security but also increase processing time. You should choose a value that makes brute force protection economically infeasible for an attacker while still delivering acceptable login latency for real users. If your hardware improves over time, you can increase the iteration count in your application config without changing the algorithm. This approach is central to robust password cracking prevention and meets modern security standards for credential storage, supporting secure password storage across all environments.

Bcrypt Hash Verifier — Check if a Password Matches a Stored Hash

Beyond generating hashes, this bcrypt password generator also lets you verify bcrypt hash values against known passwords. Run the password hash generator to produce a test hash for verifying your application's hashing implementation.

Use it to validate existing bcrypt hashes or verify existing bcrypt hashes during development: paste an existing hash into the verifier input, enter the candidate plain text password, and the tool will confirm whether they match.

How Hash Verification Works Without Decryption

This is where bcrypt's design becomes elegant. To verify hash correctness, the tool extracts the salt embedded directly inside the stored hash string, re-hashes your candidate password using that same salt and the cost factor encoded in the hash, then compares the result. If the outputs match, the password is valid. If not, it is rejected.

Crucially, you cannot decrypt a bcrypt hash — it is a one-way function by design. The underlying cipher is a cryptographic function built on a one-way hashing principle: it is computationally infeasible to invert. This makes it fundamentally different from password encryption, where a key could theoretically reverse the process. A bcrypt hash checker can only confirm a match; it cannot recover the original text.

This also means that if you need to check if a bcrypt hash matches a credential during a cross-browser testing session, you must always know the original plaintext — there is no shortcut. A bcrypt tester or bcrypt password checker operates exclusively by re-computation, never by decryption.

What Is Bcrypt and How Does It Generate Password Hashes with the Bcrypt Algorithm?

Bcrypt is an adaptive hashing algorithm designed by Niels Provos and David Mazières, introduced in 1999. It was built on the Blowfish cipher — a symmetric block cipher chosen for its expensive key setup phase, which translates directly into a slow and deliberately costly hashing process. This property, known as key stretching, is what separates bcrypt from older, weaker methods and makes it recommended for password hashing as a standard for credential storage today, aligning with modern security standards.

Unlike md5, sha1, or sha256 — all of which are general-purpose digest implementations optimised for speed — bcrypt is specifically engineered as a secure hashing function for passwords. Speed is the enemy of password security: a fast hash means an attacker can test billions of guesses per second using commodity hardware. Bcrypt's adjustable rounds make that attack economically impractical. You should stop using weak hashing algorithms like md5, sha1, or sha256 for credentials immediately. Always use trusted libraries for creating credential digests, and always use trusted libraries for anything going to production.

What Is Password Hashing and Why Is It a One-Way Process?

Credential hashing is the one-way process of securing plain text password data by creating a bit string of a fixed size — called a hash — using a cryptographic hash function. Cryptographic hash functions designed to be a one-way function are, by definition, functions which are infeasible to invert. When you generate bcrypt hash output from a string, you are performing one-way encryption: the output is deterministic given the same salt, but the salt is random, so the same password produces a different hash every time.

This is the foundation of secure credential storage. Instead of storing the plain text password itself (catastrophic if your database is breached) or using reversible encryption (still dangerous if keys are stolen), your application stores only the hash — essential when storing passwords in databases securely. During login, the supplied password is re-hashed and compared. Database security improves dramatically because stolen hashes alone are not enough to recover credentials. User credential protection and data protection both depend on this model being correctly implemented. Evaluating password strength before hashing is equally important, since a strong hash cannot compensate for a weak or guessable password.

Credential hashing should not be confused with key derivation for encryption keys, though the functions overlap. Bcrypt is specifically tuned for the credential use case: memory-hard, adjustable in cost, and resistant to GPU-based attacks in ways that simple SHA-family functions are not. The growing need of strong password hashing algorithms has driven adoption of alternatives like scrypt and argon2; indeed, password hashing scrypt bcrypt and argon2 each have scenarios where one excels over another, with argon2 named the final PHC winner on 20 July 2015.

The Password Hashing Competition and Bcrypt's Recognised Status

The Password Hashing Competition, organised by cryptography and security experts, was an open competition to raise awareness of the need for strong credential protection algorithms and to identify hash functions that can be recognized as a recommended standard. While argon2 was named the final PHC winner on 20 July 2015, bcrypt remains widely deployed and trusted across millions of production systems due to its long track record and broad library support. Understanding this history helps you appreciate why cybersecurity professionals continue to recommend bcrypt over legacy options.

Is This bcrypt generator Tool Safe to Use?

Yes — this tool is designed with data privacy as a first-class concern. All client-side hashing runs entirely within your browser via the bcryptjs library; no data is sent to any servers. We do not store any passwords, never. This browser-based utility model means that even sensitive test credentials never leave your machine, making it appropriate for developer tools workflows where security testing demands confidentiality.
Note, however, that this tool is primarily intended for testing and learning. For production use, you should implement bcrypt directly in your application using a trusted library appropriate to your language stack. This bcrypt hash tester tool is not suitable for hashing large files, non-password binary data, or anything that requires reversible operations — it is a one-way encryption utility for credential data exclusively.

Bcrypt Libraries for Secure Hashing in PHP, Java, and Node.js

Once you understand how to use this bcrypt hash generator & verifier to generate password hashes online, the next step is to implement bcrypt in your application using the appropriate language library. Always rely on a trusted library rather than implementing the algorithm yourself.

Protecting Passwords with Bcrypt in PHP (PHP 5.5+)

// Hash
$hash = password_hash($plaintext, PASSWORD_BCRYPT, ['cost' => 12]);

// Verify
$match = password_verify($plaintext, $hash);

Bcrypt PHP support is built into the language since PHP 5.5 via the native password_hash() and password_verify() functions — no external dependency required. PHP automatically generates a cryptographically secure random salt and embeds the cost factor in the output hash string. The PASSWORD_BCRYPT constant guarantees the $2y$ prefix, which is interoperable with $2b$ hashes for practical purposes. For the full reference, see the official PHP password_hash documentation.

How to Use Bcrypt for Credential Hashing in Java (Spring Security)

// Hash
String hash = encoder.encode(plaintext);

// Verify
boolean match = encoder.matches(plaintext, hash);

Bcrypt Java support is most commonly accessed through Spring Security's BCryptPasswordEncoder class. Instantiate it with an optional strength parameter corresponding to the rounds value (e.g. new BCryptPasswordEncoder(12)). If you are not using Spring, standalone Java libraries such as jBCrypt provide the same functionality. See the Spring Security password storage documentation for the full API reference.

Bcrypt in Node.js — Zero to Hashing in Under 10 Minutes (npm install bcrypt)

// Hash
const hash = await bcrypt.hash(plaintext, 12);

// Verify
const match = await bcrypt.compare(plaintext, hash);

Bcrypt Node.js implementation is available through the popular bcrypt npm package (or the pure-JavaScript bcryptjs alternative, which powers this very tool). The second argument to bcrypt.hash() is the salt rounds value. For most Node.js applications, 10–12 is the right starting point. See the bcrypt npm package page and the bcryptjs npm package page for full API documentation.

Across all three environments, the pattern is the same: hash on registration, compare on login, never store the plain text password. This is the bedrock of server-side security and credential security for any modern application.

Resources for Bcrypt Specifications and Secure Password Hashing

Developing a deeper understanding of how bcrypt works at the cryptographic level — and how to use it responsibly in production — benefits from reading the original specifications and curated articles.

Bcrypt Specifications PDF on GitHub — The original bcrypt specifications PDF by Provos and Mazières, detailing the Eksblowfish key schedule and the full bcrypt design. Essential reading if you want to understand the adaptive hashing approach at a mathematical level.
Reference C Implementation of Bcrypt — The canonical reference C implementation of bcrypt and accompanying bcrypt source code, useful for understanding the low-level mechanics and verifying library correctness.
Strong Random Password Generator — Before you hash a password, make sure it is worth hashing. A secure password generator producing credentials containing special characters, lowercase and uppercase letters and numbers is the first line of defence. Use a strong random password generator to create credentials that are resistant to dictionary attacks before they ever reach the hashing layer.
Secure password hashing in 2019 — A comprehensive guide to choosing between modern hashing options, recognized as a recommended standard reference by many practitioners. The landscape of scrypt, bcrypt, and argon2 is covered in detail, helping you understand when to prefer one approach over another based on your threat model.

For cross-browser testing scenarios, a bcrypt generator can be useful when your test suite needs to seed databases with valid hashed credentials. Using a bcrypt encoder in cross-browser testing allows you to pre-generate hashes at a known cost option and embed them in fixtures, ensuring authentication tests run consistently across environments. Browser-based utilities like this bcrypt hash generator & verifier and other online security tools make it possible to generate and validate those fixtures without spinning up a local environment. Developer utilities of this kind are a standard part of modern web developer tools workflows, complementing your IDE, debugger, and CI pipeline.

Foundational Rules. Remember these foundational rules for secure credential protection in any application: always use trusted libraries for creating password hashes; stop using weak hashing algorithms such as md5, sha1, and sha256 for credential storage; always choose a strong password; and always verify that your authentication flow correctly validates hashed passwords before deploying to production. Following these secure coding practices protects both your users and your platform from the most common credential-based attacks.

Frequently Asked Questions

What is bcrypt?: Bcrypt is a password hashing function designed to be computationally intensive and resistant to brute-force attacks. It incorporates a salt to protect against rainbow table attacks and a cost factor that lets you increase the hashing work over time as hardware gets faster. It is widely used for securely storing passwords in databases.
How many rounds (cost factor) should I use?: A cost factor of 12 is the recommended minimum for production environments as of current best practices. Higher values increase security but also increase processing time exponentially — each increment doubles the computation time. For most modern servers, 12 to 14 provides a good balance of security and performance.
Is this bcrypt generator secure to use?: Yes. All hashing and verification processing happens entirely within your browser using the bcryptjs JavaScript library. No data is transmitted to any server or stored anywhere. Your passwords and hashes never leave your device.
Can I use this tool in production?: This tool is primarily intended for testing, learning, and development purposes. For production applications, you should implement bcrypt hashing server-side using a trusted library in your programming language (e.g., bcrypt for Node.js, bcrypt for PHP, or Spring Security for Java) to ensure hashes are generated and compared securely within your own environment.
What is password hashing and why is it important?: Password hashing is a one-way cryptographic process that converts a plain text password into a fixed-length string called a hash. Because it is a one-way function, the original password cannot be derived from the hash. This means even if a database is breached, attackers cannot easily recover the actual passwords.
Why does bcrypt always produce a different hash for the same input?: Bcrypt automatically generates a unique random salt each time it hashes a string. This salt is embedded into the resulting hash string. Even if two users have the same password, their bcrypt hashes will be different, making precomputed rainbow table attacks ineffective.
How do I verify a bcrypt hash?: To verify a bcrypt hash, use the Verify Hash section: paste your existing bcrypt hash into the 'Bcrypt Hash' field and enter the original plain text password. The tool will compare them and tell you whether the text matches the hash. Bcrypt extracts the embedded salt from the hash to perform the comparison correctly.
What does the bcrypt hash string format look like?: A bcrypt hash looks like: $2a$12$N9qo8uLOickgx2ZMRZoMyeIjZAgcfl7p92ldGxad68LJZdL17lhWy. The prefix '$2a$' indicates the bcrypt algorithm version, '12' is the cost factor, the next 22 characters are the base64-encoded salt, and the remaining characters are the hashed password. The total length is always 60 characters.