How to Integrate AWS S3 with Bubble

Why AWS S3 Instead of Bubble's Built-In Storage?

Bubble stores uploaded files on its own servers and serves them through its own CDN. For most apps, this works fine. But Bubble's file storage has limitations that become problems at scale. Upload size limits can be restrictive for video-heavy apps. There's no built-in image transformation (resizing, format conversion, thumbnail generation). You can't easily set fine-grained access controls on individual files. And if you ever need to migrate away from Bubble, extracting all your files is a separate project.

AWS S3 solves all of these. It's the industry standard for file storage with virtually unlimited capacity, fine-grained IAM permissions, lifecycle policies for automatic archival, and direct integration with CloudFront CDN for global delivery. When paired with Bubble, it gives you enterprise-grade file management while Bubble handles the application logic and UI.

What You Can Build With S3 and Bubble

The most common use case is a document management system. Legal tech, healthcare, and compliance apps need to store sensitive documents with strict access controls, audit logs, and retention policies. S3 provides all of this out of the box. You upload documents from Bubble to S3, store the S3 URL and metadata in Bubble's database, and serve files through pre-signed URLs that expire after a set time.

Second is image-heavy platforms. If you're building a marketplace, portfolio site, or social platform in Bubble, you need image resizing, format optimization (WebP conversion), and fast delivery. S3 paired with a Lambda function or CloudFront function can automatically generate thumbnails and optimized versions of every uploaded image.

Third is video hosting. Bubble's file storage isn't designed for large video files. S3 handles multi-gigabyte uploads through multipart upload, and you can connect it to AWS MediaConvert for transcoding or serve videos directly through CloudFront with adaptive bitrate streaming.

Setting Up AWS S3 with Bubble

Start by creating an AWS account and an S3 bucket. Choose a region close to your users for better latency. For bucket settings, disable "Block all public access" if you need publicly readable files (like product images), or keep it blocked if all files should be private (like user documents).

Create an IAM user specifically for your Bubble integration. Never use your root AWS credentials. The IAM user needs a policy that grants s3:PutObject, s3:GetObject, s3:DeleteObject, and s3:ListBucket permissions scoped to your specific bucket. Generate an access key and secret key for this user.

In Bubble's API Connector, AWS S3's REST API uses AWS Signature Version 4 for authentication, which is complex. Each request needs a signed authorization header that includes your access key, a date stamp, the region, and a hash of the request body. Bubble can't natively generate AWS Signature V4 headers, so you have three practical approaches.

Approach one: use a Bubble plugin. The "S3 File Uploader" plugin handles the signature generation and provides a file upload element that sends files directly from the user's browser to S3. This is the fastest path for most builders. The plugin manages pre-signed upload URLs and returns the S3 file URL to your Bubble workflow.

Approach two: use pre-signed URLs generated by a Lambda function. Create a simple AWS Lambda function that generates pre-signed upload URLs. Call this function from a Bubble backend workflow via API Gateway. The function returns a temporary URL that allows a single file upload directly to S3. Your Bubble front-end then uploads the file to that URL using a multipart form or the S3 upload plugin.

Approach three: proxy uploads through a middleware. If you need server-side processing (virus scanning, metadata extraction) before storing files, route uploads through a Lambda function or EC2 instance that receives the file, processes it, then stores it in S3. This adds latency but gives you full control over the upload pipeline.

Direct Browser Upload with Pre-Signed URLs

The most efficient architecture for Bubble apps is direct browser-to-S3 upload using pre-signed URLs. The flow works like this: your Bubble app calls a backend API (Lambda via API Gateway or your own endpoint) that generates a pre-signed PUT URL for S3. This URL includes all the authentication information embedded in the query string, so the browser can upload directly to S3 without knowing your AWS credentials.

The pre-signed URL is time-limited (typically five to fifteen minutes) and scoped to a specific S3 key (file path). Your Bubble workflow generates the URL, passes it to the front end, and a JavaScript snippet or plugin performs the actual upload. When the upload completes, you store the S3 file URL in your Bubble database.

For downloads of private files, you use the same pre-signed URL approach but for GET requests. When a user needs to view or download a file, your Bubble backend generates a pre-signed GET URL with a short expiration (one to twenty-four hours) and displays it as a link or image source. This ensures files are only accessible to authenticated users for a limited time.

Connecting S3 to CloudFront for Performance

If you're serving files publicly (product images, marketing assets), put CloudFront in front of your S3 bucket. CloudFront caches files at edge locations worldwide, so users download from a server near them instead of making a round trip to your S3 region. Setup involves creating a CloudFront distribution with your S3 bucket as the origin. Use an Origin Access Identity to ensure files are only served through CloudFront, not directly from S3.

In your Bubble app, replace S3 URLs with CloudFront URLs. Instead of https://your-bucket.s3.amazonaws.com/image.jpg, use https://d1234abcdef.cloudfront.net/image.jpg. The performance improvement is significant — page load times drop noticeably when serving images through a CDN versus directly from S3.

Common Pitfalls

CORS configuration is the number one issue. If you're uploading directly from the browser to S3, your bucket needs CORS rules that allow requests from your Bubble app's domain. Without proper CORS headers, browser uploads fail silently or with cryptic errors. Configure CORS in your S3 bucket settings to allow PUT and GET methods from your Bubble domain.

The second pitfall is not setting content types correctly on upload. If you upload a PNG image to S3 without specifying Content-Type: image/png, S3 stores it as application/octet-stream. When you try to display it in Bubble using an image element, the browser might download it instead of rendering it. Always include the correct Content-Type header or metadata when generating pre-signed upload URLs.

Cost management is also important. S3 storage is cheap, but request costs and data transfer costs add up. If your app serves thousands of images daily, the data transfer fees from S3 to the internet can be significant. CloudFront actually reduces costs because cached files don't incur S3 data transfer charges for repeat downloads.

Finally, don't forget lifecycle policies. If your app generates temporary files, thumbnails, or processing artifacts, configure S3 lifecycle rules to automatically delete or archive files after a set period. Without lifecycle management, your storage costs grow indefinitely.

DIY vs Hiring a Bubble Developer

Using a Bubble plugin for S3 uploads is achievable for any Bubble builder — expect a few days of setup. Direct browser upload with pre-signed URLs requires some JavaScript comfort and AWS configuration knowledge. The Lambda function setup for generating pre-signed URLs pushes you slightly outside pure no-code territory.

For production apps with security requirements (HIPAA-compliant document storage, access logging, encryption at rest), the AWS configuration becomes the complex part, not the Bubble integration. You need proper IAM policies, encryption settings, bucket policies, and often VPC endpoints. An experienced developer handles this in days. Learning it from scratch takes weeks.

Scale Your Bubble App's File Storage

Related guides:

• Bubble firebase integration guide

• how to build a podcast platform with Bubble

• Bubble google sheets integration guide

AWS S3 removes the file storage ceiling from your Bubble app. Whether you need secure document management, image optimization, or video hosting, S3 provides the infrastructure that scales with your product. Talk to our team at Goodspeed Studio about setting up S3 properly for your Bubble application.