What are common reasons for 'QuotaExceededError' in IndexedDB, and how do you handle it?

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ICSM Computer · Answer

A QuotaExceededError in IndexedDB happens when the browser denies a write operation because your app has exceeded its allowed storage quota. It’s a
storage limit issue and can be tricky, especially for offline-first apps.and 
Here's what causes it and how to handle it:
Common Causes of QuotaExceededError
Cause
Description
Too much data
You're trying to store more than the browser allows
Blob or large JSON payloads
Storing images, videos, or large arrays/objects
No user interaction yet
Storage quota is lower if the user hasn’t interacted with your app
Private/Incognito mode
Browsers severely restrict IndexedDB size in incognito (sometimes andlt;1MB)
Shared quota limit
Your app shares a quota with other apps on the domain
Quota exceeded globally
The device’s total disk quota (not just your site) is full
Typical Limits (Approximate)
Browser
Persistent
Temporary (Default)
Incognito
Chrome
Up to 60% of free disk (with user permission)
~50MB–2GB
0–1MB
Firefox
~2GB or more
~50MB default
0–1MB
Safari
50MB (auto prompt at 5MB)
Very strict
0MB
📌 By default, most storage is temporary and limited unless 
user grants permission (e.g. via Persistent Storage API)
How to Handle It Gracefully
1. Catch the Error
Wrap writes in a try/catch block:
try {
  await db.items.bulkPut(largeData);
} catch (e) {
  if (e.name === 'QuotaExceededError') {
    alert('Storage limit exceeded. Try clearing old data or use less offline space.');
    // Optional: trigger cleanup or switch to cloud-only mode
  } else {
    throw e;
  }
}
2. Estimate Available Storage
Use the StorageManager API:
if (navigator.storage andand navigator.storage.estimate) {
  const { quota, usage } = await navigator.storage.estimate();
  console.log(`Used ${(usage / quota * 100).toFixed(2)}% of quota`);
}
3. Request Persistent Storage (Chrome, Edge)
if (navigator.storage andand navigator.storage.persist) {
  const isPersisted = await navigator.storage.persist();
  if (isPersisted) {
    console.log("Persistent storage granted");
  } else {
    console.warn("Persistent storage denied");
  }
}
May increase available quota significantlyRequires HTTPS and user interaction
4. Store Smaller Data
Compress large payloads (e.g., JSON, text) before savingStore images/files as references (e.g., upload to server) instead of full blobsAvoid saving large media directly in IndexedDB unless absolutely needed
5. Clean Up Unused Data
Implement data expiration or LRU (Least Recently Used) cache patterns:
// Example: delete items older than 30 days
const cutoff = Date.now() - 30 * 24 * 60 * 60 * 1000;
await db.items.where('updatedAt').below(cutoff).delete();
6. Limit Sync Queue Size
If using a sync queue (e.g. offline-first apps), cap it:
const count = await db.syncQueue.count();
if (count andgt; 1000) {
  await db.syncQueue.limit(100).delete(); // keep only recent
}

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What are common reasons for 'QuotaExceededError' in IndexedDB, and how do you handle it?

ICSM Computer

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1 Answers

Common Causes of `QuotaExceededError`

Typical Limits (Approximate)

How to Handle It Gracefully

1. Catch the Error

2. Estimate Available Storage

3. Request Persistent Storage (Chrome, Edge)

4. Store Smaller Data

5. Clean Up Unused Data

6. Limit Sync Queue Size

Liked By

Cause	Description
Too much data	You're trying to store more than the browser allows
Blob or large JSON payloads	Storing images, videos, or large arrays/objects
No user interaction yet	Storage quota is lower if the user hasn’t interacted with your app
Private/Incognito mode	Browsers severely restrict IndexedDB size in incognito (sometimes <1MB)
Shared quota limit	Your app shares a quota with other apps on the domain
Quota exceeded globally	The device’s total disk quota (not just your site) is full

Browser	Persistent	Temporary (Default)	Incognito
Chrome	Up to 60% of free disk (with user permission)	~50MB–2GB	0–1MB
Firefox	~2GB or more	~50MB default	0–1MB
Safari	50MB (auto prompt at 5MB)	Very strict	0MB