Argon2id Hash Generator
Generate and verify Argon2id password hashes directly in your browser. Configure memory, iterations, parallelism, hash length, and a unique salt. Copy the encoded hash for password storage or the raw hexadecimal result for testing.
Calculations run locally in your browser. Avoid entering real production passwords into online tools.
19.0 MiB
Use a unique random salt for each password. The default is 16 bytes.
What is Argon2id?
Argon2id is a memory-hard password hashing and key derivation algorithm. Argon2 won the Password Hashing Competition in 2015 and is specified in RFC 9106. Argon2id combines data-independent and data-dependent memory access to balance resistance to side-channel attacks and password cracking.
Unlike fast general-purpose hashes such as SHA-256, Argon2id deliberately consumes configurable CPU time and memory, making large-scale password guessing more expensive.
Argon2id parameters
- Memory (m): RAM used by the computation, measured in KiB. For example, 19456 KiB equals 19 MiB.
- Iterations (t): Number of passes over the memory.
- Parallelism (p): Number of lanes. The underlying browser implementation computes lanes without necessarily using multiple CPU threads.
- Salt: A unique random value for each password. The generator defaults to 16 bytes.
- Hash length: Size of the derived hash in bytes; 32 bytes is a common choice.
The default settings of m=19456, t=2, p=1 correspond to one configuration documented in the OWASP Password Storage Cheat Sheet. They are a starting point, not a substitute for benchmarking on your own server.
How to use the generator
- Enter a test password.
- Adjust the parameters or keep the defaults.
- Use Random to generate a new salt when needed.
- Select Calculate Argon2id hash.
- Copy the encoded hash or raw hexadecimal output separately.
To verify a password, open Verify password, enter the candidate password and its existing Argon2 encoded hash, and select Verify password.
Encoded hash format
A standard PHC-style Argon2id hash looks like:
$argon2id$v=19$m=19456,t=2,p=1$<salt>$<hash>
It includes the algorithm, version, cost parameters, salt, and derived hash. Salt and hash are represented using unpadded Base64. Because the salt is random, hashing the same password twice normally produces different encoded results.
Security considerations
Hashing is not encryption: an Argon2id hash cannot be decrypted to recover a password. An attacker may still guess candidate passwords and compare hashes. Use strong passwords and tune parameters to the resources and authentication workload of your server.
The calculator runs locally in the browser using WebAssembly. However, browser extensions, compromised devices, or third-party scripts can undermine the privacy of any online password tool. Do not enter production passwords into this or any public website. For production authentication, use a maintained server-side password-hashing library and follow its verification API.
High memory settings can be slow or fail on devices with limited RAM.
Frequently asked questions
Is Argon2id better than SHA-256 for passwords?
Yes. SHA-256 is intentionally fast and is not suitable for storing passwords by itself. Argon2id is designed for password hashing and makes large-scale guessing more expensive.
Why does the same password produce different hashes?
A new random salt changes the output. The encoded hash stores the salt so the password can still be verified later.
Can Argon2id hashes be reversed?
No practical reversal operation exists. Weak passwords may nevertheless be discovered by guessing and verifying candidate values.
Can I verify an Argon2i or Argon2d hash?
Yes. The verifier accepts encoded Argon2id, Argon2i, and Argon2d hashes using version 19.
Related tools
- SHA-256 hash calculator — Calculate a general-purpose cryptographic hash.
- SHA-2 hash calculator — Compare multiple SHA-2 output lengths.
- Password generator — Create strong random passwords.
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