This either means that the username and password information in your wp-config.php file is incorrect or that contact with the database server at localhost could not be established. This could mean your host’s database server is down.

 

The WordPress error:

“Error establishing a database connection”

means WordPress can’t connect to your MySQL database. This is almost always caused by one of these 5 issues.

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✅ Step-by-Step Fix

1️⃣ Check Your wp-config.php Credentials (Most Common Issue)

Open your wp-config.php file (in your WordPress root folder).

Look for:

define('DB_NAME', 'database_name');
define('DB_USER', 'database_username');
define('DB_PASSWORD', 'database_password');
define('DB_HOST', 'localhost');

✔ Verify:

• Database name is correct
• Username is correct
• Password is correct
• DB host is correct

🔎 Where to confirm?

Log into your hosting control panel (cPanel / Plesk / hosting dashboard) → MySQL Databases → confirm:

• Database exists
• User exists
• User is assigned to database
• Password matches

If unsure, reset the database user password and update wp-config.php.

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2️⃣ Confirm the Database Server Host

Most hosts use:

localhost

But some use something different, like:

• 127.0.0.1
• mysql.yourdomain.com
• A specific IP address

Check your hosting provider documentation or ask support.

If you’re on managed WordPress hosting (like WP Engine or SiteGround), the DB host is often not localhost.

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3️⃣ Check If MySQL Server Is Down

Try creating a file called test.php in your WordPress root:

<?php
$link = mysqli_connect('localhost', 'username', 'password');
if (!$link) {
    die('Could not connect: ' . mysqli_connect_error());
}
echo 'Connected successfully';
?>

Replace credentials.

If it fails → database server is likely down.
Contact your hosting provider.

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4️⃣ Check If Database Is Corrupted

Add this line to wp-config.php:

define('WP_ALLOW_REPAIR', true);

Then visit:

yourdomain.com/wp-admin/maint/repair.php

Run repair.

After finishing, remove the line from wp-config.php.

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5️⃣ Check If You’ve Hit Hosting Limits

On shared hosting:

• Too many connections
• Memory limit reached
• Server overload

Check your hosting dashboard → resource usage.

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6️⃣ If This Happened After Migration

Common causes:

• Wrong DB host
• Forgot to import database
• Database user not assigned
• Old credentials in wp-config.php

If you migrated manually or via plugin, re-check:

• Database imported successfully
• wp-config.php updated

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🔎 Quick Diagnosis Table

Situation	Most Likely Cause
Frontend broken but admin works	Corrupted database
Both broken immediately after moving site	Wrong DB credentials
Random intermittent error	Server overload
Just changed password	wp-config.php not updated

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⚡ Fastest Fix (90% of cases)

1. Reset database user password
2. Reassign user to database
3. Update wp-config.php
4. Save
5. Refresh site

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