---
title: "What are the security and privacy considerations when using IndexedDB?"  
description: "What are the security and privacy considerations when using IndexedDB?"  
author: "Ponu Maurya"  
published: 2025-07-03  
updated: 2025-07-03  
canonical: https://www.mindstick.com/interview/34312/what-are-the-security-and-privacy-considerations-when-using-indexeddb  
category: "database"  
tags: ["database", "indexeddb"]  
reading_time: 5 minutes  

---

# What are the security and privacy considerations when using IndexedDB?

When using **IndexedDB**, security and privacy are critical concerns—especially for apps storing sensitive user data. Here are the key considerations:

## 1. Same-Origin Policy

- **Each origin (protocol + domain + port)** has its own **isolated IndexedDB**.
- One site **cannot access** the IndexedDB data of another site.
- This prevents cross-site data leakage.

## 2. No Built-in Encryption

- Data in IndexedDB is **not encrypted by default**.
- If you're storing **sensitive data** (like tokens, passwords, PII):

   - Use **client-side encryption** before storing.
   - Use the [Web Crypto API](https://developer.mozilla.org/en-US/docs/Web/API/Web_Crypto_API) to encrypt/decrypt.

```plaintext
// Encrypt data before storing (example only, not production-safe)
const encoder = new TextEncoder();
const data = encoder.encode("secret message");
// Use subtleCrypto for real encryption
```

## 3. Storage Persistence

- Data is stored **persistently** (survives tab close, restart, etc.).
- But:

   - Browsers **may clear** data if the device is low on storage (especially on mobile).
   - You can request **persistent storage**:

```plaintext
navigator.storage.persist().then(granted => {
    console.log(granted ? "Persistent storage granted" : "Not granted");
});
```

## 4. No Access Control (Auth)

- IndexedDB does **not have access control**.
- Any JavaScript running in the same origin can access the DB.
- If you load **third-party scripts**, they could potentially access your DB if not sandboxed.

> **Mitigation:** Never expose IndexedDB to untrusted scripts.

## 5. Private/Incognito Mode

- IndexedDB is usually supported in incognito/private mode.
- However:

   - Data is **wiped** after the session.
   - Some browsers may **disable** or restrict its behavior.

## 6. Fingerprinting Risks

- IndexedDB can be used for **tracking users**:

   - Storing unique IDs
   - Checking if a DB or key exists to re-identify users

- **Browser privacy tools** (like Brave, Safari) may **isolate** or limit IndexedDB for this reason.

## 7. Storage Size Limits

- IndexedDB quotas vary:

   - Usually **5–50MB** per origin without user prompt
   - Higher on desktop with user interaction

- Exceeding limits can cause `QuotaExceededError`.

## Best Practices Summary

| Recommendation | Why |
| --- | --- |
| Use HTTPS | Prevent man-in-the-middle attacks |
| Encrypt sensitive data | Protect user info if device is compromised |
| Request persistent storage | Ensure offline data survives |
| Avoid untrusted scripts | Prevent unauthorized DB access |
| Use clear versioning strategy | Avoid upgrade errors |
| Be mindful of fingerprinting | Respect user privacy |

## Answers

### Answer by Ponu Maurya

When using **IndexedDB**, security and privacy are critical concerns—especially for apps storing sensitive user data. Here are the key considerations:

## 1. Same-Origin Policy

- **Each origin (protocol + domain + port)** has its own **isolated IndexedDB**.
- One site **cannot access** the IndexedDB data of another site.
- This prevents cross-site data leakage.

## 2. No Built-in Encryption

- Data in IndexedDB is **not encrypted by default**.
- If you're storing **sensitive data** (like tokens, passwords, PII):

   - Use **client-side encryption** before storing.
   - Use the [Web Crypto API](https://developer.mozilla.org/en-US/docs/Web/API/Web_Crypto_API) to encrypt/decrypt.

```plaintext
// Encrypt data before storing (example only, not production-safe)
const encoder = new TextEncoder();
const data = encoder.encode("secret message");
// Use subtleCrypto for real encryption
```

## 3. Storage Persistence

- Data is stored **persistently** (survives tab close, restart, etc.).
- But:

   - Browsers **may clear** data if the device is low on storage (especially on mobile).
   - You can request **persistent storage**:

```plaintext
navigator.storage.persist().then(granted => {
    console.log(granted ? "Persistent storage granted" : "Not granted");
});
```

## 4. No Access Control (Auth)

- IndexedDB does **not have access control**.
- Any JavaScript running in the same origin can access the DB.
- If you load **third-party scripts**, they could potentially access your DB if not sandboxed.

> **Mitigation:** Never expose IndexedDB to untrusted scripts.

## 5. Private/Incognito Mode

- IndexedDB is usually supported in incognito/private mode.
- However:

   - Data is **wiped** after the session.
   - Some browsers may **disable** or restrict its behavior.

## 6. Fingerprinting Risks

- IndexedDB can be used for **tracking users**:

   - Storing unique IDs
   - Checking if a DB or key exists to re-identify users

- **Browser privacy tools** (like Brave, Safari) may **isolate** or limit IndexedDB for this reason.

## 7. Storage Size Limits

- IndexedDB quotas vary:

   - Usually **5–50MB** per origin without user prompt
   - Higher on desktop with user interaction

- Exceeding limits can cause `QuotaExceededError`.

## Best Practices Summary

| Recommendation | Why |
| --- | --- |
| Use HTTPS | Prevent man-in-the-middle attacks |
| Encrypt sensitive data | Protect user info if device is compromised |
| Request persistent storage | Ensure offline data survives |
| Avoid untrusted scripts | Prevent unauthorized DB access |
| Use clear versioning strategy | Avoid upgrade errors |
| Be mindful of fingerprinting | Respect user privacy |


---

Original Source: https://www.mindstick.com/interview/34312/what-are-the-security-and-privacy-considerations-when-using-indexeddb

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