Fix AWS Error 403: Access Denied (S3 & Console)

Updated: 11/29/2025

You try to upload a file to an S3 bucket or view a cloud resource, and the AWS Console blocks you with: 'Error: Access Denied (Service: Amazon S3; Status Code: 403)'. This is the most common permission error in cloud computing. It means your IAM User identity exists, but it lacks the specific s3:PutObject or s3:ListBucket permission required to touch that resource.

Table of Contents

Method 1: Check 'Block Public Access' Settings

If you are trying to view a file via a public URL, AWS blocks this by default for security.

Step 1: Open Bucket Permissions

Go to the S3 Console, click your bucket name, and select the Permissions tab.

Step 2: Edit Public Access

Look for 'Block public access (bucket settings)'. If 'Block all public access' is On, nobody (including you via browser link) can view files. Click Edit and uncheck it ONLY if you intend for the files to be public.

Method 2: Update IAM Policy

Your user account might be missing the rights.

{ "Effect": "Allow", "Action": "s3:*", "Resource": "arn:aws:s3:::your-bucket-name/*" }

Ensure your IAM Admin attaches a policy like the one above to your user profile in the IAM Dashboard.

Method 3: Check Encryption (KMS)

If the bucket is encrypted with a custom KMS key, you need permissions for BOTH the bucket and the key.

If you have S3 access but lack kms:Decrypt permissions, you will still get a 403 Error when trying to download or view the file.