Do You Need a Backend for Your App?

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After building your app in Rork, use this documentation to decide if your app needs a backend or can stay local only.

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Summary

Rork helps you build beautiful and cohesive frontend mobile applications. A frontend application is usually something that is user facing, like the interactions of an app, the styles of a website design, or the components that build up your app. A **backend **is for the background functionalities. Like any data manipulation, data storage, or authentication that is needed for a frontend to work. Not every frontend application needs a backend. By the end, you’ll know exactly which category your idea falls into — and what to do next to finish your Rork app. Requirements

• A Rork project
• A general idea of your app’s function

Table of Contents

1. What Counts as “No Backend”
2. Apps That Always Need a Backend
3. Gray-Zone Apps (Optional Backend)

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1. What Counts as “No Backend”

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Local-Only Apps (Everything Stays on the Device)

These are apps that store all their data on the user’s phone.
No sync needed. No logins required. No sharing implemented. Examples:

• Todo lists
• Notes apps
• Journals
• Habit trackers
• Mood logs
• Calculators
• Timers
• Unit converters
• Offline flashcards
• Photo filters/AI Gen
• Utility widgets

Rork can build and store the data needed for all of these with no backend at all, using:

• LocalStorage
• Secure key-value stores

As long as the data never leaves the device, you’re good to use local storage. If your application is currently not saving data locally, just ask the Rork prompt editor: “Please make sure the data is being stored locally and persists”

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Tools With Temporary / Non-Persistent Data

These apps don’t care about storing long-term state at all. Examples:

• Playground apps (Drawing, sandbox)
• Local mini-games
• One-off AI generators (That dont need to store)
• Fun tools that create something but don’t need to remember it like Shazam

If nothing needs to persist after the app closes then no backend is needed to store or manipulate anything. Most simple applications built on Rork will behave like this by default.

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AI Apps That Only Call an External API

If your app just sends a prompt to GPT and returns the response: You do not need a backend. You’re just making requests to OpenAI or another AI provider. Backend becomes optional only when:

• You want user history
• You want personalization
• You want usage tracking

This extends to any external API. As long as you do not need to store this data, then feel free to use any API without a backend.

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2. Apps That Always Need a Backend

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Apps With Accounts or Login

If the user “has an account,” you need:

• Authentication
• Restoring user data
• Sync across devices

Examples:

• Social apps
• Productivity apps with cloud sync
• Finance apps
• Any multi-device workflow

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Apps That Sync Across Devices

A user writes a note on their phone and expects it on their laptop.
That requires:

• Database
• Cloud sync
• Persistent storage

A backend is required.

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Apps With Sharing, Collaboration, or Multiplayer

If more than one person can see, edit, or comment on the same thing:

• Messaging
• Friends lists
• Comments
• Posts
• Social Feeds
• Real-time collaboration
• Matchmaking like Dating apps

All of this needs a backend.

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Apps That Store Files

If your app handles:

• Images
• Videos
• PDFs
• Audio recordings

…and these files need to persist across different devices, you need to use a backend. Local storage will not cut it for cross-device or sharable content.

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Apps With Security or Access Rules

If the app enforces any rule between users:

• Blocking
• Moderation
• Rate limiting
• Anti-spam

Client-only apps can’t enforce rules. A backend would be required.

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3. Gray-Zone Apps (Optional Backend)

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Local-First Apps With Optional Sync Later

Some apps work great without a backend, then add cloud features later. Examples:

• Journal → adds cloud backup
• Notes app → adds multi-device sync
• Offline photo editor → adds “share to cloud”

You can ship v1 with no backend and add sync when you grow.

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AI Apps With Memory or Personalization

You can choose:

• Local-only memory → no backend
• Cloud memory across devices → backend
• Personalized models → backend

Your v1 can be simple with local, once you get users, you can move to a more secure advanced system like Cloud or Personalized. Have you figured out if your app needs a backend? Great news. We have a document to help you do just that on both Superbase and Firebase. Check them out here.

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Building your backend with Rork