bcrypt vs argon2 vs scrypt: Password Hashing in 2026

TL;DR

For new projects in 2026: use Argon2id. OWASP, NIST, and virtually every security authority recommends it as the gold standard for password hashing. bcrypt is still safe but limited to 72-byte passwords and was designed in 1999. scrypt is solid but less widely reviewed than Argon2. If you're on bcrypt today, it's fine to stay — but new code should default to Argon2id.

Key Takeaways

Argon2id: OWASP's #1 recommendation — winner of the Password Hashing Competition (PHC), memory-hard, GPU-resistant
bcrypt: Still safe, proven over 25 years, but 72-byte max and no parallelism parameter
scrypt: Memory-hard like Argon2 but fewer tuning options and less peer-reviewed
npm packages: bcrypt (~1.8M/wk), bcryptjs (~3.2M/wk pure-JS, slower), argon2 (~850K/wk)
Never use: MD5, SHA-1, SHA-256 for passwords — they're too fast (built for speed, not security)
All three are fine for existing production systems — priority for new code: Argon2id

The Fundamental Rule

Password hashing is not the same as regular hashing (SHA-256, MD5). A password hash needs to be:

Slow on purpose — to resist brute-force attacks
Memory-hard — to defeat GPU/ASIC acceleration
Salted — to prevent rainbow table attacks

SHA-256 can hash 1 billion passwords per second on a GPU. bcrypt can hash ~20. Argon2id can hash ~1 (with proper settings). That difference is the entire security story.

Download Trends

Package	Weekly Downloads	Language	Notes
`bcryptjs`	~3.2M	Pure JavaScript	Slower, no native deps
`bcrypt`	~1.8M	C++ bindings	Faster, requires node-gyp
`argon2`	~850K	C++ bindings	OWASP recommended
`@node-rs/argon2`	~120K	Rust via napi-rs	Fastest Argon2 impl
`scrypt-js`	~4.1M	Pure JavaScript	Used by ethers.js (wallets)

scrypt-js downloads are inflated by crypto/wallet libraries, not password hashing use cases.

bcrypt

bcrypt was designed in 1999 and has been scrutinized by the security community for 25+ years. No significant vulnerabilities have been found.

import bcrypt from "bcrypt"

// Hashing (async — never use sync in request handlers)
const SALT_ROUNDS = 12 // 2^12 iterations — ~250ms on modern hardware

async function hashPassword(plaintext: string): Promise<string> {
  return bcrypt.hash(plaintext, SALT_ROUNDS)
}

async function verifyPassword(
  plaintext: string,
  hash: string
): Promise<boolean> {
  return bcrypt.compare(plaintext, hash)
}

// Usage:
const hash = await hashPassword("hunter2")
// "$2b$12$..." — bcrypt hash with embedded salt and cost factor

const valid = await verifyPassword("hunter2", hash)  // true
const invalid = await verifyPassword("wrong", hash)   // false

bcrypt limitations:

72-byte truncation: bcrypt silently truncates passwords to 72 bytes. "password_with_very_long_suffix_that_exceeds_72_bytes_total" and "password_with_very_long_suffix_that_exceeds_72_bytes_alter" hash to the same value.

// Mitigation: pre-hash with SHA-256 (not ideal but works)
import { createHash } from "crypto"

function preprocess(password: string): string {
  return createHash("sha256").update(password).digest("hex")
}
// Then: bcrypt.hash(preprocess(password), SALT_ROUNDS)

No memory-hardness: Modern GPUs can run many bcrypt instances in parallel. Cost factor 12 provides good protection today but may weaken as hardware improves.
Cost factor only: Single parameter to tune speed — no separate memory or parallelism controls.

When bcrypt is fine:

Existing production systems — don't migrate just to migrate
Projects where native C++ dependencies are a problem (use bcryptjs instead)
Teams where bcrypt expertise exists and Argon2 is unfamiliar

Argon2

Argon2 won the Password Hashing Competition in 2015, specifically designed to address bcrypt's limitations.

import argon2 from "argon2"

// Argon2id (the recommended variant — hybrid of Argon2i and Argon2d)
async function hashPassword(plaintext: string): Promise<string> {
  return argon2.hash(plaintext, {
    type: argon2.argon2id,
    memoryCost: 65536,  // 64 MB — OWASP minimum recommendation
    timeCost: 3,        // iterations
    parallelism: 4,     // threads
  })
}

async function verifyPassword(
  plaintext: string,
  hash: string
): Promise<boolean> {
  return argon2.verify(hash, plaintext)
}

// Hash format: $argon2id$v=19$m=65536,t=3,p=4$<salt>$<hash>
// All parameters are embedded — verify() auto-reads them

Three Argon2 variants:

Argon2id — Use this. Hybrid of the other two, recommended by OWASP for password hashing
Argon2i — Optimized against side-channel attacks; used for password-based key derivation (not password storage)
Argon2d — Maximizes GPU resistance; not recommended for password hashing (vulnerable to side-channel)

OWASP 2026 minimum settings:

Argon2id: m=19456 (19MB), t=2, p=1  — fast devices (login endpoints)
Argon2id: m=65536 (64MB), t=3, p=4  — higher security contexts

Argon2 advantages over bcrypt:

No password length limit
Memory-hard — resistant to GPU/ASIC attacks
Three tunable parameters: memory, time, parallelism
PHC winner — extensively peer-reviewed since 2015
RFC 9106 standardized (2021)

scrypt

scrypt is the memory-hard algorithm used in Litecoin and many cryptocurrency wallets. Node.js has it built in:

import { scrypt, randomBytes, timingSafeEqual } from "crypto"
import { promisify } from "util"

const scryptAsync = promisify(scrypt)

// OWASP recommended parameters: N=32768 (2^15), r=8, p=1
const N = 32768  // CPU/memory cost
const r = 8      // block size
const p = 1      // parallelism
const KEYLEN = 64

async function hashPassword(plaintext: string): Promise<string> {
  const salt = randomBytes(32).toString("hex")
  const derivedKey = await scryptAsync(plaintext, salt, KEYLEN, { N, r, p }) as Buffer
  return `${salt}:${derivedKey.toString("hex")}`
}

async function verifyPassword(
  plaintext: string,
  storedHash: string
): Promise<boolean> {
  const [salt, hash] = storedHash.split(":")
  const derivedKey = await scryptAsync(plaintext, salt, KEYLEN, { N, r, p }) as Buffer
  const storedKey = Buffer.from(hash, "hex")
  return timingSafeEqual(derivedKey, storedKey)
}

Note: scrypt has no standard hash encoding format — you must store salt separately (as shown above) or implement your own format. This is a footgun compared to bcrypt and Argon2, which embed salt in the hash string.

scrypt compared to Argon2:

Less peer-reviewed than Argon2
Memory requirement = N * r * 128 bytes — less intuitive to reason about
No recommended parameters from PHC (there was no competition winner)
Still technically sound, widely used in crypto wallets

Security Comparison

Property	bcrypt	Argon2id	scrypt
OWASP recommended	⭐⭐⭐ (2nd tier)	⭐⭐⭐⭐⭐ (1st tier)	⭐⭐⭐⭐ (2nd tier)
Memory-hard	❌	✅	✅
GPU-resistant	⚠️ Moderate	✅ Strong	✅ Strong
Max password length	72 bytes	None	None
Salt handling	Auto-embedded	Auto-embedded	Manual
Standardized	No formal RFC	RFC 9106	RFC 7914
Peer review	25+ years	10 years (PHC)	15+ years
Tuning	Cost factor only	Memory + time + threads	Cost + block + threads

Performance Benchmarks

Approximate timing on modern hardware (Apple M3, measuring one hash operation):

Algorithm	Settings	Time	Memory Used
bcrypt	cost=10	~65ms	<1MB
bcrypt	cost=12	~250ms	<1MB
Argon2id	m=64MB, t=3	~180ms	64MB
Argon2id	m=19MB, t=2	~55ms	19MB
scrypt	N=32768	~120ms	32MB

Target: 100–300ms per hash operation is the accepted sweet spot for login endpoints.

Recommended Settings by Use Case

// Login endpoint (high-volume, need responsiveness):
const LOGIN_SETTINGS = {
  type: argon2.argon2id,
  memoryCost: 19456,  // 19MB
  timeCost: 2,
  parallelism: 1,
}

// Admin/high-value accounts (can afford more time):
const ADMIN_SETTINGS = {
  type: argon2.argon2id,
  memoryCost: 65536,  // 64MB
  timeCost: 3,
  parallelism: 4,
}

// Password reset / account creation (one-time, latency acceptable):
const HIGH_SECURITY_SETTINGS = {
  type: argon2.argon2id,
  memoryCost: 131072,  // 128MB
  timeCost: 4,
  parallelism: 4,
}

Migrating from bcrypt to Argon2

Don't rehash all passwords at once — use a lazy migration on login:

import bcrypt from "bcrypt"
import argon2 from "argon2"

async function loginUser(plaintext: string, storedHash: string) {
  let verified = false

  if (storedHash.startsWith("$2b$") || storedHash.startsWith("$2a$")) {
    // Legacy bcrypt hash
    verified = await bcrypt.compare(plaintext, storedHash)

    if (verified) {
      // Upgrade to Argon2id on successful login
      const newHash = await argon2.hash(plaintext, {
        type: argon2.argon2id,
        memoryCost: 65536,
        timeCost: 3,
        parallelism: 4,
      })
      await updateUserPasswordHash(userId, newHash)
    }
  } else if (storedHash.startsWith("$argon2")) {
    // New Argon2 hash
    verified = await argon2.verify(storedHash, plaintext)
  }

  return verified
}

This migrates users transparently over time with zero downtime.

When to Use Each

Choose Argon2id if:

Starting any new project in 2026
You want OWASP-compliant password storage
You need fine-grained tuning (memory, time, parallelism)
You want protection against GPU/ASIC brute-force

Choose bcrypt if:

You're maintaining an existing bcrypt-based system
Native C++ dependencies are blocked (use bcryptjs)
Your passwords are guaranteed to be under 72 bytes (or you pre-hash)

Use scrypt if:

You're building something in the cryptocurrency/Web3 space (convention)
You specifically need the built-in Node.js crypto module (no external deps)

Never use for passwords:

MD5, SHA-1, SHA-256, SHA-512 — too fast, designed for data integrity not passwords
PBKDF2 — technically OWASP-compliant but inferior to Argon2 and bcrypt

Methodology

Security recommendations sourced from OWASP Password Storage Cheat Sheet (2025 update), NIST SP 800-63B, and RFC 9106 (Argon2). Download counts represent npm weekly averages (February 2026). Performance benchmarks measured with node:crypto and argon2 npm package on Apple M3 hardware.

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