What is Session Storage Viewer
The Session Storage Viewer is a client-side inspection tool that reads and displays every key-value pair currently stored in the browser's sessionStorage for the current tab. Like the Local Storage Viewer, it scans the storage on load and presents the entries in a table format with key and value columns. The critical difference from localStorage is that sessionStorage is scoped to the browser tab — entries are cleared when the tab is closed, and each tab has its own independent sessionStorage even if they share the same origin. This makes sessionStorage ideal for temporary state like form progress, multi-step wizard data, or tab-specific preferences. The viewer helps you understand what temporary state your application is maintaining and verify that tab isolation is working correctly.
How to Use Session Storage Viewer
- Step 1: Open the Session Storage Viewer. The tool immediately scans sessionStorage and displays all entries in a table.
- Step 2: Review the entries: each row shows a key name and its stored value. The header displays the total number of entries.
- Step 3: To test tab isolation, open the same tool in a new tab — it will show a different set of entries (or be empty if nothing has been stored in that tab).
- Step 4: Note that closing the tab will clear all sessionStorage entries permanently.
Why Use Session Storage Viewer
sessionStorage is often misunderstood — developers confuse it with localStorage or assume it persists across tabs. The Session Storage Viewer makes the behavior concrete and visible: you can see exactly what is stored in the current tab, verify that opening a new tab gives a clean slate, and confirm that closing a tab removes the data. This is essential for debugging multi-tab workflows, form state management, and any application that uses sessionStorage for temporary caching. The tool is also useful for security auditing — verifying that sensitive data like CSRF tokens or temporary auth state is properly scoped to individual tabs and does not leak across browsing contexts.
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
How is this different from the Local Storage Viewer?
<p>localStorage persists across tabs and browser sessions; sessionStorage is scoped to the current tab and cleared when the tab closes. The two tools are identical in functionality but read from different browser storage APIs.</p>
Can I edit sessionStorage entries?
<p>The viewer is read-only. For editing, use the browser DevTools Application tab or call sessionStorage.setItem() from the console.</p>
Does sessionStorage persist after refreshing the page?
<p>Yes. Refreshing the page does not clear sessionStorage. Only closing the tab (not refreshing) removes the entries.</p>
Why would I use sessionStorage instead of localStorage?
<p>Use sessionStorage when data should be temporary and tab-scoped: multi-step form progress, tab-specific UI state, or one-time tokens that should not persist across tabs. Use localStorage for data that should survive browser restarts.</p>
Can I transfer sessionStorage data between tabs?
<p>Not directly — sessionStorage is isolated per tab. You would need to use BroadcastChannel or localStorage as an intermediary to pass data between tabs.</p>
How much data can sessionStorage hold?
<p>The storage limit is typically 5MB per origin per tab, similar to localStorage. However, the exact limit varies by browser. The Storage Manager API (navigator.storage.estimate()) can report the actual usage for your browser.</p>