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bcrypt vs bcryptjs: Which Node.js Password Hashing Library Should You Use?
Choose bcrypt when your Node.js deployment can install native modules. Choose bcryptjs when a pure JavaScript dependency makes installation or deployment simpler. Both libraries use the bcrypt format, so each can verify a hash made by the other.
bcrypt vs bcryptjs at a glance
| Question | bcrypt | bcryptjs |
|---|---|---|
| Implementation | Native Node.js addon | Pure JavaScript |
| Install requirement | Prebuilt binary or a working native build toolchain | JavaScript package only |
| Speed | Usually faster | Usually slower |
| Hash compatibility | Verifies bcryptjs hashes | Verifies bcrypt hashes |
| Best fit | Typical Node.js server | Restricted builds and JavaScript-only runtimes |
The choice depends on deployment constraints and CPU budget, not different password-hashing security goals.
What changes between bcrypt and bcryptjs
The bcrypt npm package uses a native addon. Its README documents prebuilt binaries for supported platforms and a source-build path when a matching binary is unavailable.
The bcryptjs package is implemented in JavaScript. Its API mirrors bcrypt closely, which keeps application code and stored hashes portable between the two packages.
Use bcrypt on a conventional Node.js service when native installs work in your build and deployment environments. Native code reduces the CPU time spent on each hash and comparison.
Use bcryptjs when native dependencies are the blocker. That includes constrained build images, environments that only allow JavaScript packages, and deployments where a native addon complicates the release path.
Can bcrypt and bcryptjs verify the same password hashes?
Yes. A fresh Node.js run with bcrypt 6.0.0 and bcryptjs 3.0.3 verified a hash from each library with the other library.
This helps when a deployment change makes you switch packages. Existing bcrypt hashes do not need to be replaced just because the application starts importing the other library.
Hash and verify a password with bcryptjs
This example uses the asynchronous API so hashing does not block the Node.js event loop. It returns true for the matching password and false for a different password.
import bcrypt from "bcryptjs";
const rounds = 12;
const password = "correct horse battery staple";
const hash = await bcrypt.hash(password, rounds);
console.log(await bcrypt.compare(password, hash));
console.log(await bcrypt.compare("wrong password", hash));
During login, pass the submitted password and stored hash to compare.
Pick the cost factor for your server
Test the cost factor on the hardware and concurrency level you plan to run, then choose a value whose response time your server can sustain.
Use asynchronous hashing on Node.js servers, and reject input above bcrypt’s 72-byte limit before hashing.
Which package should you install?
Install bcrypt for a standard Node.js backend that supports native modules. Install bcryptjs when avoiding a native build is more important than the added CPU cost.
npm install bcrypt
# or
npm install bcryptjs
Do not import both in the same authentication path without a deployment reason. Pick one package, keep your cost-factor policy explicit, and test login against existing hashes before you release.
Is bcryptjs secure?
bcryptjs implements bcrypt in JavaScript. Its security properties depend on bcrypt configuration and application handling, while its performance is typically lower than the native bcrypt package.
Can bcryptjs verify bcrypt hashes?
Yes. bcryptjs and bcrypt use compatible bcrypt hash formats, so each package can verify a hash created by the other when the password is the same.
Should I use bcrypt or bcryptjs in Node.js?
Use bcrypt for a Node.js server that can install native modules. Use bcryptjs when a pure JavaScript dependency removes a deployment or build constraint.
