What is Local Storage Manager
The Local Storage Manager is a client-side CRUD (Create, Read, Update, Delete) interface for the browser's localStorage API. Unlike the Local Storage Viewer which only displays entries, this tool provides full write access: you can create new key-value pairs, update existing ones, and delete individual entries or clear the entire storage. The interface consists of two input fields (key and value), a Set button that writes the entry, a Clear All button that removes everything, and a scrollable list of all current entries with individual delete links. The tool refreshes the list after every write operation, so you see the result of your action immediately. Errors (such as localStorage being full) are caught and displayed as alerts. This tool is essential for testing how your application handles various localStorage states — you can inject test values, simulate storage-full scenarios, or clean up stale entries during development.
How to Use Local Storage Manager
- Step 1: Open the Local Storage Manager. You will see two input fields (key and value), a Set button, a Clear All button, and a list of all current localStorage entries.
- Step 2: To add or update an entry: type a key name in the first field, the desired value in the second field, and click Set. If the key already exists, its value is overwritten.
- Step 3: To delete a single entry: click the red 'del' link next to any entry in the list. The entry is immediately removed from localStorage and the list refreshes.
- Step 4: To clear all entries: click the Clear All button. This removes every key-value pair from localStorage for this origin — use with caution as this is irreversible.
Why Use Local Storage Manager
Testing application behavior with specific localStorage states is a daily need during web development. You might need to simulate a logged-in state by injecting an auth token, test how the app handles an empty localStorage, verify that cache invalidation works by modifying a cached value, or clean up developer-only test entries. The Local Storage Manager makes all of these operations trivial — type, click, done. Without it, you would need to open browser DevTools, navigate to the Application tab, find Local Storage, and manually edit entries one at a time. The tool's immediate refresh after each operation also provides visual confirmation that the write succeeded, which is especially helpful when debugging localStorage quota exceeded errors.
Privacy & Security
This tool runs entirely in your browser — no data ever leaves your device. There is no server round-trip, no upload, no logging, and no account required. Your input is processed locally using client-side JavaScript and is never stored, transmitted, or accessible to anyone else. When you close the tab, everything disappears.
Frequently Asked Questions
Can I edit existing values directly in the list?
<p>Currently, the tool does not support inline editing. To update a value, type the key name and new value in the input fields and click Set — this overwrites the existing value.</p>
What happens if localStorage is full?
<p>The tool catches the QuotaExceededError from localStorage.setItem() and displays it as an alert. You would need to delete some entries (using the del links) before adding new ones.</p>
Does Clear All affect sessionStorage?
<p>No. Clear All only calls localStorage.clear(), which removes all entries from localStorage. sessionStorage is a separate storage area and is not affected.</p>
Is there a way to export all entries?
<p>Not currently. You could copy the output from the Local Storage Viewer tool and save it as a JSON file for backup purposes.</p>
What data types can I store?
<p>localStorage stores strings only. If you store a JSON object, it is automatically stringified. The tool stores whatever text you enter in the value field — there is no type validation.</p>