Postgres MD5 Password Hash Generator

Need a Postgres MD5 password hash generator that never sends your password over the wire in clear text? Enter an account name and a password, and the tool returns the exact md5 string PostgreSQL stores, plus a ready-to-run statement, all calculated in your browser.

How the Postgres MD5 Password Hash Generator Works

PostgreSQL does not store the password you type. It stores a short verifier, and for the md5 scheme that verifier is the literal text md5 followed by 32 hexadecimal characters. A PostgreSQL MD5 password generator like this one needs only two inputs, and it reproduces that exact calculation locally, so the string you take away is the same value the server would have computed itself. The result is a one-way hash: you cannot run it backwards to recover the password, only recompute it from a guess. Because nothing leaves your machine, your credentials and your privacy stay intact from the first keystroke to the last, which matters when the same md5 hash will later sit in migration files and backups. It only takes a moment to generate an ntlm hash, and nothing you enter ever leaves your device.

Why Pre-Encoded Passwords Keep Plaintext Out of Logs

When you run CREATE USER app PASSWORD 'secret', the full statement travels to the Postgres server as text. With statement logging switched on, the plaintext lands in the server logs, and a connection pooler or proxy in the middle may record it as well. A pre-encoded value avoids the problem: the server sees only the md5 string, recognises it as already encrypted, and stores it untouched. Database dumps and shell history then hold the hash, never the original password. Compare that with the plain form of the statement, and the benefit is obvious: the md5 hash is all that ever gets recorded.

The Username Acts as the Salt

Unlike modern schemes, the md5 format uses no random salt. The account name is glued onto the password before hashing, so two accounts that share a password still get different hashes. That is why the same password typed for reporting_svc and for analytics_svc produces two unrelated results, and why you must enter the exact, case-sensitive username the account will use. Change one character of the name and the hash no longer matches.

Postgres Password Generator: Step-by-Step Usage

Using the Postgres password generator takes under a minute. Work through the fields in this order: The wordpress password hash generator runs entirely client-side — nothing you enter or generate is ever stored or transmitted.

1. Type the exact account name of the account, such as reporting_svc. It feeds the hash, so spelling and case both matter.
2. Enter the password you want, or let the tool suggest one (see the section on choosing a secret below).
3. Click the Generate button to compute the PostgreSQL MD5 password hash.
4. Copy the md5 string, or grab the complete SQL statement that wraps it.
5. Run that statement in psql or your migration tool, then connect with the original password to confirm it works.

Choosing a Random Password

If you do not have a password yet, generate Postgres password candidates with a high-entropy mix of character sets. Length beats cleverness: a 14-character random string with letters, digits and symbols is far harder to guess than a short phrase with forced capitals. NIST guidance discourages arbitrary composition rules, so pick a password length you can store in a password manager and let randomness do the work. The generator hashes whatever you enter here together with the account name, so the md5 verifier it returns is only as strong as this input. Avoid reusing a value across environments, and never paste a production secret into a tool you do not trust.

PostgreSQL Password Hashing Formula and Worked Example

The whole scheme fits on one line. The stored value is the prefix md5 joined to the MD5 digest of the password concatenated with the username:

$$\text{stored hash} = \texttt{md5} + \operatorname{MD5}(\text{password} + \text{username})$$

Here is a complete calculation with values chosen for this guide. The account is reporting_svc and the password is Tq7!mVx2#Lp9wZ (14 characters).

Run the same password for analytics_svc and you get md54f11604d335f8778b77b7a06c3b18097; for the default postgres superuser you get md5991613b7b4f59bab8f2d428f84833c8c. Same password, three different results, because only the account name changed.

CREATE USER and ALTER USER with a Hash

Paste the finished value straight into either statement. PostgreSQL checks the start of the string: anything beginning with md5 followed by 32 hex digits is treated as an already encrypted password and saved as is.

CREATE USER reporting_svc PASSWORD 'md580db9109343fa687dc4e165f27d3adff';
ALTER USER reporting_svc PASSWORD 'md580db9109343fa687dc4e165f27d3adff';

Both forms work identically. Use ALTER ROLE if you prefer the generic keyword; USER is simply a wrapper that adds the login attribute. You can also set expiry with VALID UNTIL, which does not change the hash itself.

Where pg_shadow Stores the Hash

The value ends up in the pg_authid catalog, which a view exposes to superusers. Run SELECT passwd FROM pg_shadow WHERE usename = 'reporting_svc' and you will see exactly the 35-character string from the table above. If it matches, your hash was accepted.

PostgreSQL Password Encryption: MD5 Versus SCRAM-SHA-256

The docs call this feature password encryption, although what happens is really one-way hashing. PostgreSQL offers two schemes, and the right one depends on your server version and clients. Here is how they compare:

SCRAM stands for salted challenge response authentication mechanism. The client proves it knows the password without sending it, and the client can verify the server too. Nothing like that exists in the md5 exchange, which is why SCRAM is the safer choice wherever your clients support it.

Why MD5 Is Legacy and Deprecated

Recent PostgreSQL releases flag md5 password support for removal, and cloud providers now advise moving to SCRAM. During a connection attempt the server sends a four-byte random salt and the client answers with md5 plus the digest of the stored hex and that salt. A salt that small gives little protection against a replay attack once an eavesdropper has captured enough exchanges, so the wire protocol only stays safe inside SSL/TLS. Treat md5 as a legacy compatibility option rather than a goal.

The password_encryption Setting

The password_encryption parameter in postgresql.conf decides what the server does with a plaintext password it receives. Set it to scram-sha-256 so new passwords are hashed with SCRAM automatically. A ready-made md5 value bypasses the setting, which is exactly why a generator is useful for older clients. Check the current value from psql before you rely on it.

Matching pg_hba.conf Rules to the Hash Type

The method in each pg_hba.conf line must fit the stored hash. A rule set to scram-sha-256 cannot authenticate an account whose password is an md5 verifier, while a rule set to md5 accepts either type and uses whichever the account holds. A role created with this tool's md5 value therefore needs a rule set to md5 (or scram-sha-256 only after you re-hash it). If logins fail after a change, compare the hash prefix with the authentication method before touching anything else.

Generate Postgres Password Hashes for a Legacy 9.6 Cluster

Priya Raman, a platform engineer at a regional freight company, has a ticket to rotate the loader credentials on a reporting cluster still running PostgreSQL 9.6. SCRAM-SHA-256 arrived in version 10, so on this cluster md5 is the only hashing option, and the ETL job's old JDBC driver would not speak SCRAM anyway. Statement logging is set to ddl, which means a plain ALTER USER would write the new password into the log file that the whole operations team can read.

She opens the generator and fills in two fields: the account name etl_loader and a new 16-character password, Wk3#vQ8nLz!4RdYt, drawn from her password manager. That is double the 8-character floor in NIST SP 800-63B, and it is random rather than patterned. Clicking the Generate button returns the md5 hash for her inputs, calculated from a 26-character concatenated string:

• Result: md53502b484f5ae2c476bcfcdc90f0ff946
• Length check: 35 characters, which is the 3-character prefix plus 32 digits
• Statement: ALTER USER etl_loader PASSWORD 'md53502b484f5ae2c476bcfcdc90f0ff946';

Priya runs the statement against a staging copy first. The log shows only the 35-character string, so nothing she would be uncomfortable seeing in a ticket. She then queries the password catalog for etl_loader and confirms the stored value matches the generated hash character for character, which proves the account name was spelled correctly. A test connection with the original 16-character password succeeds.

The result tells her two things: the rotation is safe to apply to production tonight, and the account stays on md5 only until the upgrade. She adds a follow-up to the upgrade plan: after the move to version 14 or later, rerun the account with password_encryption set to SCRAM and retire the md5 value.

Is an MD5 Password Generator Safe to Use?

Safe in two senses: the tool itself, and the hash it produces. The tool runs in your browser, so no password is transmitted. The hash is a different story. Because the digest is a single fast round, it is highly exposed to brute force, and attackers can use precomputed lookup tables built from common passwords. Names such as admin and postgres appear often as salts, which weakens them further.

A leaked hash is also enough to authenticate on some setups, and it is open to an offline attack that costs the attacker nothing. Pre-encoding protects against log exposure, not against theft of the catalog or a database backup. Pick a long random secret, restrict who can read the password catalog, and plan a move to SCRAM. This security trade-off is the honest summary: better than plaintext, worse than modern alternatives.

Automating Password Hashing in Application Code

You do not have to use a web form for every account. Official and community libraries expose the same calculation. The C library libpq ships a function that prepares an encrypted password for either scheme, and psycopg offers an equivalent helper in Python. Passlib includes a postgres_md5 hasher for verifying existing hashes. Each of them returns the same md5 string this generator shows, so you can cross-check a library's output against the tool. Infrastructure tools such as Terraform can then receive only the hash, so the plaintext never enters your repository.

• Provisioning: generate the md5 value locally, commit only that value, and apply it with a migration.
• Rotation: rotate a credential by issuing a new statement; there is no need to restart anything.
• Auditing: compare the prefix of each stored value with a generated one to find accounts still on md5.

Troubleshooting Your PostgreSQL Password Generator Results

When a freshly generated hash is rejected, the cause is almost always one of a few mismatches. Work through them in order before assuming the tool is wrong.

The Hash Works but the Login Still Fails

Confirm that the account name in the form is identical to the one in the statement. The md5 hash is computed from the password plus the account name, so a trailing space, a capital letter or a quoted identifier in either one changes the concatenated string and therefore the digest. Then confirm that the password you type at the prompt is the one you hashed, not a similar value from another environment. If both match, check that the rule in your authentication file uses the md5 method for that connection.

Password Expiration and VALID UNTIL

PostgreSQL does not reset an expired password for you. If you set VALID UNTIL on the account, password expiration simply blocks new password logins after that date, whatever hash is stored. A correct hash on an expired account looks exactly like a wrong one from the client's side, so check the expiry date with a catalog query before regenerating anything. Setting a new date and re-running the statement is enough; the hash itself needs no change.

Privacy of Database Users and Their Hashes

Treat the string this generator returns as sensitive even though it is not the password itself. When it leaks, the hash can be attacked offline. Hashes for database users should live in access-controlled secrets storage, not in tickets or chat. Offline guessing runs at whatever speed the attacker can afford, so improving security means short retention, narrow access and a plan to replace md5 accounts with SCRAM-based ones as soon as your client drivers allow it. Rotating a credential costs one statement; recovering from a leaked one costs much more.

PostgreSQL Password Generator Best Practices

Follow these best practices whenever you create or change an account password:

• Keep generated md5 values out of tickets and chat, and use a unique, long secret per environment.
• Enable SSL/TLS so credentials and traffic are protected from eavesdroppers.
• Apply the passwordcheck module to enforce complexity for typed-in passwords.
• Plan the move from the md5 value to SCRAM, then review who holds administrator rights and monitor logs for unauthorized login attempts.
• Treat any password that has appeared in a log or chat as compromised and replace it.

Because the generator runs locally like an open-source style helper, the only artifact to protect is the hash it produces. Keep the configuration that holds generated hashes in your repository, with no plaintext beside it.

Frequently Asked Questions

Why does the hash depend on the username too?

PostgreSQL includes the role (user) name in the hash input specifically so the same password produces a different stored hash for every different user -- this means two users who happen to choose the same password don't end up with identical hash values in pg_authid, which would otherwise leak that information.

Is this still used by modern PostgreSQL?

It's still supported for backward compatibility, but PostgreSQL 10+ recommends scram-sha-256 authentication instead, which is a proper salted, iterated, standards-based password verifier (RFC 5802) rather than a single unsalted-beyond-username MD5 pass. New setups should prefer scram-sha-256.

Is this hash format secure?

Not by modern standards -- MD5 is a fast hash, and using the username as the only "salt" is far weaker than a proper random salt, since usernames are often known or guessable. This tool exists for compatibility with existing PostgreSQL md5-auth setups, not as a security recommendation.

Where would I use this generated hash?

In PostgreSQL's pg_authid system catalog (via ALTER ROLE ... PASSWORD, when the server's password_encryption setting is md5) or when manually constructing an entry for a tool that needs to match PostgreSQL's legacy md5 authentication format directly.

Is my password sent anywhere?

No. The hash is computed entirely in your browser -- nothing is transmitted to a server or stored.