How to Handle Blob Storage in Bubble

Bubble automatically stores uploaded files on Amazon S3 and serves them via CDN. Files uploaded through the File Uploader or Picture Uploader are stored and referenced by URL in your database. The storage limits depend on your plan: Free = 0.5 GB, Starter = 10 GB, Growth = 100 GB, Team = 1 TB. You can view and manage stored files in the Data tab → File manager. Bubble's built-in storage works for most apps, but large file volumes or files over 50MB may require external storage.

In the Plugins tab, open the API Connector. Create a new API called 'AWS_S3'. Set authentication to 'None / self-handled' since you will add AWS Signature headers manually. For a simpler approach, create a backend API workflow that generates a pre-signed upload URL using an AWS Lambda function or a third-party service like Uploadcare. The pre-signed URL lets the browser upload directly to S3 without exposing your AWS credentials.

1{
2  "bucket": "your-bucket-name",
3  "key": "uploads/user-files/{{filename}}",
4  "content_type": "application/octet-stream",
5  "expiration": 3600
6}

Add a File Uploader element on your page. When the user selects a file, trigger a workflow that: Step 1 — calls your backend workflow to get a pre-signed S3 upload URL. Step 2 — uses the API Connector to PUT the file to the pre-signed URL (set the file as the body, content-type matching the file type). Step 3 — stores the S3 file URL in your database on the relevant record. For files under 50MB, you can upload through Bubble's native uploader first, then transfer to S3 via a backend workflow.

For private files that should not be publicly accessible, generate signed download URLs. Create a backend API workflow that takes a file key as a parameter, generates a pre-signed GET URL from S3 with an expiration time (e.g., 1 hour), and returns the URL. On the frontend, call this workflow when the user clicks a download or view button. The signed URL gives temporary access without exposing the file publicly.

For large files, implement chunked uploads by splitting files into parts and uploading them sequentially. Use S3's multipart upload API for files over 100MB. For frequently accessed files, enable CloudFront CDN in front of your S3 bucket. Store file metadata (size, type, upload date) in your Bubble database while keeping the actual file in S3. This gives you fast metadata queries without loading large files.