🔐 Password Hash Verifier – Multi-Algorithm Browser Tool
The Password Hash Verifier is a fully client-side tool that lets you confirm whether a plaintext password corresponds to a stored cryptographic hash. All computation runs in your browser using bcryptjs, hash-wasm, the Web Crypto API, and CryptoJS — your password never leaves your device.
🔎 Supported Algorithms
The tool covers the full spectrum of password-hashing algorithms in active use today:
| Algorithm | Hash Format / Detection | Strength | Recommended |
|---|---|---|---|
| bcrypt | $2a$ / $2b$ / $2y$ prefix | Strong | ✅ Yes |
| Argon2id | $argon2id$ PHC string | Very Strong | ✅ Yes (preferred) |
| Argon2i / Argon2d | $argon2i$ / $argon2d$ PHC string | Very Strong | ✅ Yes |
| PBKDF2 | Hex / Base64 + manual params | Acceptable–Strong | ✅ With ≥600k iterations |
| scrypt | Hex + manual params (N, r, p) | Strong | ✅ Yes |
| SHA-256 / SHA-512 | 64 / 128 hex chars | Acceptable | ⚠️ Only with salt + stretching |
| SHA-1 | 40 hex chars | Broken | ❌ No |
| MD5 | 32 hex chars | Broken | ❌ No |
⚙️ How Verification Works
For self-describing formats like bcrypt and Argon2, the hash string itself encodes all the parameters needed to reproduce it — cost factor, memory, salt, and version. The tool parses these automatically:
$argon2id$v=19$m=65536,t=3,p=4$c29tZXNhbHQ$RdescudvJCsgt3ub...Breaking this down: argon2id is the variant, v=19 is the version, m=65536 is memory (64 MB), t=3 is 3 iterations, p=4 is parallelism, followed by the Base64-encoded salt and hash digest.
For parameterless formats (SHA-256, MD5, etc.) the tool simply hashes your password with the selected algorithm and compares the resulting hex string to the stored value. For PBKDF2 and scrypt, you must supply the salt and work factors separately since they are not embedded in a standard format.
🏎️ Algorithm Comparison
Not all password-hashing algorithms are created equal. The key properties that make an algorithm suitable for password storage are:
Memory hardness:
Argon2 and scrypt require large amounts of RAM, making GPU-based brute-force attacks extremely expensive.
Adaptive cost:
bcrypt, Argon2, and scrypt let you tune the work factor so the hash takes ~1 second on your hardware, and you can increase it as hardware improves.
Built-in salt:
bcrypt, Argon2, and scrypt always embed a random salt — preventing rainbow-table attacks automatically.
GPU resistance:
MD5, SHA-1, and plain SHA-256/512 can be computed billions of times per second on consumer GPUs, making them unsuitable for passwords.
🔬 Auto-Detection
Paste a hash string and click "Auto-Detect" — the tool reads the prefix to identify bcrypt ($2a$, $2b$, $2y$) and Argon2 ($argon2id$, $argon2i$, $argon2d$). For hex digests, auto-detection uses the character length to guess the algorithm (32 → MD5, 40 → SHA-1, 64 → SHA-256, 128 → SHA-512), with a manual override available for ambiguous cases.
⏱️ Timing & Performance
The tool displays wall-clock verification time in milliseconds. Adaptive algorithms like bcrypt and Argon2 are intentionally slow — a typical bcrypt cost-12 hash takes 200–400 ms. This computational cost is a feature, not a bug: it means an attacker must spend the same time on every guessed password.
🚨 Security Advisories
💡 Common Use Cases
- Debugging authentication: Verify that your application is hashing passwords the same way your database stores them.
- Database auditing: Quickly confirm whether a known test password matches a stored hash without running your full application stack.
- Security education: Compare the hashing speed of MD5 vs. bcrypt vs. Argon2 side by side to understand why algorithm choice matters.
- Legacy system analysis: Identify and document weak algorithms in systems you are auditing or migrating.