---
title: "What happens if a user disables storage or clears site data?"  
description: "What happens if a user disables storage or clears site data?"  
author: "ICSM Computer"  
published: 2025-07-04  
updated: 2025-07-04  
canonical: https://www.mindstick.com/interview/34316/what-happens-if-a-user-disables-storage-or-clears-site-data  
category: "database"  
tags: ["database", "indexeddb"]  
reading_time: 5 minutes  

---

# What happens if a user disables storage or clears site data?

When a user **disables storage** or **clears site data**, your **IndexedDB data can be lost or made inaccessible**, depending on the action and browser.

Here’s a breakdown of what happens:

## 1. User Clears Site Data (via browser settings)

When a user clears site data (cookies, local storage, cache, etc.), this typically includes:

| Storage Type | Is it Cleared? |
| --- | --- |
| Cookies | ✅ Yes |
| LocalStorage | ✅ Yes |
| IndexedDB | ✅ Yes |
| Cache Storage | ✅ Yes |
| Service Workers | ✅ Yes |

### Impact on IndexedDB:

## All databases and object stores are deleted

- Next time the app loads, `indexedDB.open()` will behave like the DB never existed (i.e., version = 0)
- You will need to recreate schema in `onupgradeneeded`

## 2. User Disables Storage (Privacy/Incognito Mode)

Some browsers (especially Safari) **restrict or block IndexedDB** in private mode:

| Browser | Behavior in Private Mode |
| --- | --- |
| Chrome | ✅ Works normally |
| Firefox | ✅ Works normally |
| Safari (iOS/macOS) | ❌ Fails or silently blocks IndexedDB |
| Brave | ⚠️ May block or isolate per-session |

### Impact:

`indexedDB.open()` may:

- Fail silently
- Throw a `QuotaExceededError`
- Return `undefined` or null
- Any attempt to store or read data **will not persist** or may crash

## 3. Automatic Eviction by the Browser

Browsers may **automatically delete data** when:

- Device is low on space (especially mobile)
- The site is inactive for a long time
- Storage is **non-persistent** (default behavior)

### To reduce risk:

You can request **persistent storage** (only works in supported browsers):

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

## Best Practices to Handle This

| Tip | Why |
| --- | --- |
| Use feature detection (`if (!window.indexedDB)`) | Avoid crashing on unsupported devices |
| Handle `onerror` on `open`, `get`, `put` | Catch failures gracefully |
| Use `onupgradeneeded` to recreate schema if DB is gone | Allows safe recovery |
| Inform users if data was cleared | Improves user experience |
| Use `navigator.storage.persist()` | Reduce risk of auto-deletion |

## Detect if Data is Lost

```javascript
indexedDB.open("MyDB").onsuccess = function (event) {
    const db = event.target.result;
    if (!db.objectStoreNames.contains("users")) {
        // Data likely cleared
        alert("App data has been reset or cleared.");
    }
};
```

## Summary

| Action | Result for IndexedDB |
| --- | --- |
| User clears browser/site data | ❌ All IndexedDB data is deleted |
| Private/incognito mode | ⚠️ IndexedDB may be disabled or wiped |
| Automatic eviction | ⚠️ Data may be deleted silently |
| Persistent storage requested | ✅ More likely to survive cleanup |

## Answers

### Answer by ICSM Computer

When a user **disables storage** or **clears site data**, your **IndexedDB data can be lost or made inaccessible**, depending on the action and browser.

Here’s a breakdown of what happens:

## 1. User Clears Site Data (via browser settings)

When a user clears site data (cookies, local storage, cache, etc.), this typically includes:

| Storage Type | Is it Cleared? |
| --- | --- |
| Cookies | ✅ Yes |
| LocalStorage | ✅ Yes |
| IndexedDB | ✅ Yes |
| Cache Storage | ✅ Yes |
| Service Workers | ✅ Yes |

### Impact on IndexedDB:

## All databases and object stores are deleted

- Next time the app loads, `indexedDB.open()` will behave like the DB never existed (i.e., version = 0)
- You will need to recreate schema in `onupgradeneeded`

## 2. User Disables Storage (Privacy/Incognito Mode)

Some browsers (especially Safari) **restrict or block IndexedDB** in private mode:

| Browser | Behavior in Private Mode |
| --- | --- |
| Chrome | ✅ Works normally |
| Firefox | ✅ Works normally |
| Safari (iOS/macOS) | ❌ Fails or silently blocks IndexedDB |
| Brave | ⚠️ May block or isolate per-session |

### Impact:

`indexedDB.open()` may:

- Fail silently
- Throw a `QuotaExceededError`
- Return `undefined` or null
- Any attempt to store or read data **will not persist** or may crash

## 3. Automatic Eviction by the Browser

Browsers may **automatically delete data** when:

- Device is low on space (especially mobile)
- The site is inactive for a long time
- Storage is **non-persistent** (default behavior)

### To reduce risk:

You can request **persistent storage** (only works in supported browsers):

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

## Best Practices to Handle This

| Tip | Why |
| --- | --- |
| Use feature detection (`if (!window.indexedDB)`) | Avoid crashing on unsupported devices |
| Handle `onerror` on `open`, `get`, `put` | Catch failures gracefully |
| Use `onupgradeneeded` to recreate schema if DB is gone | Allows safe recovery |
| Inform users if data was cleared | Improves user experience |
| Use `navigator.storage.persist()` | Reduce risk of auto-deletion |

## Detect if Data is Lost

```javascript
indexedDB.open("MyDB").onsuccess = function (event) {
    const db = event.target.result;
    if (!db.objectStoreNames.contains("users")) {
        // Data likely cleared
        alert("App data has been reset or cleared.");
    }
};
```

## Summary

| Action | Result for IndexedDB |
| --- | --- |
| User clears browser/site data | ❌ All IndexedDB data is deleted |
| Private/incognito mode | ⚠️ IndexedDB may be disabled or wiped |
| Automatic eviction | ⚠️ Data may be deleted silently |
| Persistent storage requested | ✅ More likely to survive cleanup |


---

Original Source: https://www.mindstick.com/interview/34316/what-happens-if-a-user-disables-storage-or-clears-site-data

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