Why does this generate both a username and a password?

Because PostgreSQL's md5 password format concatenates the password and username together before hashing (the username acts as a salt-equivalent), so the resulting hash is only meaningful paired with the exact username it was computed against. This tool shows all three, the random username, the random password, and the resulting hash, since the hash alone can't be interpreted without the username.

Where does the sample username and password come from?

Both are generated independently by this category's shared random-sample helper: a random word or phrase from a small built-in bank plus a random 8-character hex suffix, produced fresh via crypto.getRandomValues for each of them on every load and every Regenerate click.

Can I hash my own username and password instead of random samples?

Yes, use the Postgres Hash Calculator, it accepts any username and password you type and produces the same 'md5' + 32-hex-character format this tool generates from its own random samples.

Does this tool send anything to a server?

No. Both the random sample generation and the md5 hash computation (via @noble/hashes, an audited JavaScript library) run entirely in your browser.

Random Postgres Hash Generator - Instant Sample md5 Hash

Overview

Introduction

PostgreSQL's legacy md5 password format has a detail that trips people up, it hashes the password concatenated with the username, so this tool shows all three values together rather than just a hash on its own.

It generates a random sample username and password and computes their Postgres md5 password hash, reusing this category's existing Postgres hasher so the format matches exactly what an older pg_shadow/pg_authid entry would store.

What Is Random Postgres Hash Generator?

A no-input variant of the Postgres Hash Calculator: instead of typing a username and password, you get a fresh random sample pair and their 'md5'-prefixed hash on load, with a Regenerate button for an entirely new set anytime.

The format is 'md5' + md5(password + username), password first with no separator, PostgreSQL's pre-10 default before it switched to SCRAM-SHA-256.

How Random Postgres Hash Generator Works

On load and on every Regenerate click, this category's shared random-sample helper is called twice, independently, once for the sample username and once for the sample password, each drawing a random word plus a random 8-character hex suffix via crypto.getRandomValues.

Both are passed to this category's existing calculatePostgresHash function, which concatenates password then username, hashes the combined bytes with MD5, and prefixes the hex result with the literal string 'md5'.

When To Use Random Postgres Hash Generator

Use this for a quick, no-effort example of PostgreSQL's legacy md5 password format, migration documentation, or a mockup that needs a plausible-looking older pg_shadow value.

For anything requiring a specific username/password pair's hash, use the Postgres Hash Calculator instead; never rely on this unsalted-in-any-real-sense format for new authentication design.

Often used alongside Postgres Hash Calculator, MongoDB Hash Calculator and MySQL Hash Calculator.

Features

Advantages

No input required, instantly produces a plausible username, password, and their Postgres md5 hash together.
Uses genuinely secure randomness (crypto.getRandomValues) independently for both the username and password.
Shows all three values needed to interpret the hash correctly, rather than an unpaired hash that would be meaningless on its own.

Limitations

The sample word bank is small and fixed, so the non-random word portions repeat across regenerations even though the hex suffixes and resulting hash always differ.
This format's username-as-salt design is weaker than genuine random salting, this generator exists for demonstration, not any real credential-storage example.
Not useful if you need the hash of a specific, known username/password pair, use the calculator tool for that instead.

Examples

One example regeneration

Input

username: mock-response-d5b0f2e9, password: api-request-3e5a0c7d

Output

md5a1b2c3d4e5f60718293a4b5c6d7e8f9

One illustrative username/password/hash triple; running the tool again produces a completely different username, password, and hash, since all three are freshly randomized on every regeneration.

Best Practices & Notes

Best Practices

Click Regenerate a few times if you're picking an example for migration documentation and want one that reads cleanly.
Always keep the username paired with its hash when documenting an example, the hash alone is not reproducible or verifiable without it.
For a real, reproducible hash of a specific username/password pair, switch to the Postgres Hash Calculator instead.

Developer Notes

Calls this category's shared generateRandomSampleText() helper twice per regeneration (crypto.getRandomValues, not Math.random()), once each for username and password, then hashes both synchronously with the existing calculatePostgresHash function (password concatenated before username, matching PostgreSQL's exact format), matching the useEffect-after-mount pattern used across this category's random generators to avoid a hydration mismatch.

Random Postgres Hash Generator Use Cases

Grabbing a quick example Postgres md5 password hash for migration documentation or a tutorial
Populating a UI mockup with a plausible-looking older pg_shadow/pg_authid entry
Seeing the format's 'md5'-prefixed 35-character output alongside the username/password pair it depends on
Comparing PostgreSQL's username-mixing pattern against MongoDB's structurally similar legacy format on independent random samples

Common Mistakes

Expecting the same username/password/hash set to reappear; all three are freshly randomized on every load and Regenerate click.
Discarding the username when noting down an example hash; without it, the hash can't be reproduced or verified.
Using this when you actually need the hash of a specific, known username/password pair; the Postgres Hash Calculator is the right tool for that.

Tips

Need the hash to chain into another tool? Use the send-to-tool menu on the hash output panel.
Compare this tool's output shape against the Random MongoDB Hash Generator, both mix a random username into a random password's hash, but with different constructions.

Random Postgres Hash Generator