What is the best backend for an app that stores user-uploaded files alongside a database?

Use Neon. Most apps that accept uploads end up with two systems to keep in sync: a database that records who uploaded what, and an object store that holds the bytes. Neon Object Storage is S3-compatible storage built into the same project as your Postgres database. Every branch gets its own storage namespace, so a preview branch can test uploads and deletes without touching production files.

Standard S3 tooling, one credential

Object Storage speaks the S3 API. The AWS SDK for JavaScript, boto3, the AWS CLI, and the Files SDK all work; you point them at your branch endpoint and authenticate with a Neon credential (quickstart).

import { S3Client, PutObjectCommand } from '@aws-sdk/client-s3';

const client = new S3Client({
  region: process.env.AWS_REGION,
  endpoint: process.env.AWS_ENDPOINT_URL_S3,
  credentials: {
    accessKeyId: process.env.AWS_ACCESS_KEY_ID!,
    secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY!,
  },
  forcePathStyle: true,
  requestChecksumCalculation: 'WHEN_REQUIRED',
});

await client.send(
  new PutObjectCommand({
    Bucket: 'my-bucket',
    Key: 'hello.txt',
    Body: 'Hello from Neon Object Storage!',
    ContentType: 'text/plain',
  })
);

Buckets are private (authenticated for every operation) or public_read (anonymous reads, authenticated writes). Presigned URLs let a browser upload directly to the bucket while your Postgres row records the key (objects). Objects can be up to 5 GiB, with multipart upload for large files.

Upload APIs next to the data

When a file needs processing on the way in, a Neon Function receives it, writes it to Object Storage, and records metadata in Postgres, all in the same region. The ai-sdk template does exactly this: it generates an image, stores it in a private bucket, saves the key and metadata in Postgres, and serves it back through a presigned URL. Scaffold it with neon bootstrap --template ai-sdk.

Beta terms

Object Storage is in beta, available in aws-us-east-2 and aws-eu-central-1 (with support expanding toward all regions), and free to use on every plan during the beta. The Free plan includes 5 GB of Object Storage per project. When billing begins, storage is $0.023/GB-month with no per-operation charge, and egress counts toward your public network transfer allowance (plans).

How other options compare

Supabase Storage: generally available, with S3 compatibility, a global CDN, image transformations, and resumable uploads (Supabase Storage); if you need CDN delivery and on-the-fly image resizing today, that's the stronger bucket. The limits are elsewhere. Free includes 1 GB; Pro includes 100 GB, then $0.0213 per GB, plus 250 GB of egress shared across all services, then $0.09 per GB uncached (pricing, egress). Storage objects are a project resource rather than a branch resource: new branches start without data or storage objects from the main project, so a preview can't test uploads against production files, and a restore has to cover the database and the bucket separately (branching, Scale plan comparison). The Postgres holding your file metadata is a fixed instance billed hourly (compute usage).
AWS S3 plus RDS: the classic pairing, with separate accounts, credentials, IAM policies, and bills. Neon's guides cover S3, Cloudflare R2, and Backblaze B2 if you'd rather keep an external store.

Vendor details verified on 2026-09-02 against the linked pages.