How SessionStorage Viewer Tool Works

This tool does not read your browser storage directly. Instead, you export your sessionStorage data from the browser console (or from automated tests), paste the JSON into the input box, and generate an analysis report. The tool validates your JSON, optionally decodes URL-encoded values, optionally pretty-prints values that contain embedded JSON strings, and then produces a formatted output you can copy or download.

The output is designed to be practical during debugging: it highlights totals, helps you spot unexpectedly large entries, and keeps the listing stable so two snapshots can be compared line by line. You can also switch formats depending on where you want to paste the result, such as Markdown for GitHub issues or CSV for spreadsheet review.

Step-by-Step

• 1. Export sessionStorage as JSON from your browser or test runner.
• 2. Paste the JSON object into the tool input (a simple key/value map).
• 3. Choose an output format (Report, JSON, Markdown, or CSV) and a sort order.
• 4. Enable optional helpers like URL decoding or JSON value parsing if your app stores encoded payloads.
• 5. Click Generate to view totals, identify large entries, and review key/value pairs.

Key Features

Snapshot-Based Viewing (No Browser Access Required)

Because it works from a pasted export, you can analyze storage from any environment: local development, staging, CI logs, or a customer-provided snapshot. This keeps the workflow predictable and avoids permission prompts, browser extensions, or differences between Chrome, Firefox, and Safari.

Snapshots also help with collaboration. A teammate can paste the same data you saw and inspect it with the same formatting, which reduces “works on my machine” friction and speeds up code reviews.

Sorting and Size Awareness

Sort keys alphabetically or by approximate byte size to quickly spot oversized values that can push you toward storage quotas. Seeing the largest entries first is especially useful when sessionStorage is used to cache API responses, store large tracking payloads, or persist step-by-step form state.

The size numbers are intended for comparison and prioritization. Even if the exact browser quota varies, the relative ranking of entries is usually what you need to decide what to trim, compress, or move to a server-side store.

Filtering for Fast Debugging

Apply a simple filter term to narrow the report to specific keys, such as auth, cart, redirect, or feature-flag prefixes. Filtering helps you focus on the part of the state that is relevant to the bug you are chasing, without deleting anything from the snapshot.

This is handy when applications namespace keys by module (for example, checkout.* or flags.*) and you want to verify whether all expected keys are present after a route transition.

Value Helpers: URL Decode and Embedded JSON Parsing

Many apps store values that are URL-encoded or JSON-serialized strings. With one click you can decode URL components for readability, and you can try parsing JSON values so complex objects become neatly formatted output rather than dense single-line strings.

These helpers make the viewer useful for both humans and automation. You can paste the report into a bug ticket for a quick read, or switch to JSON output for programmatic comparison in scripts and test assertions.

Copy, Download, and Share

Generated output is designed to be copied into tickets, pull requests, and incident notes. You can also download the output as a text file to attach to a report or to keep a record of a session snapshot during testing. The download feature is especially convenient when you run the tool repeatedly while iterating on a fix and want to archive “before” and “after” snapshots.

Use Cases

• Authentication troubleshooting: Verify whether tokens, refresh markers, or login redirects are stored under the expected keys, and confirm that values are not stale across navigation events.
• Checkout and multi-step flows: Inspect the temporary state used to persist form steps, shipping options, promo codes, or payment intents between page loads in a single tab session.
• Feature flags and experiments: Review experiment assignments, cohort IDs, and rollout toggles to confirm a user is in the right variant and that flag evaluation happened at the right time.
• UTM and attribution debugging: Decode URL-encoded campaign parameters to confirm they are captured correctly, not double-encoded, and not overwritten by subsequent page views.
• Performance and quota checks: Identify unusually large values that can slow reads/writes or risk hitting storage limits on certain browsers, especially on mobile devices.
• Customer support snapshots: Ask a user to export sessionStorage and share it (after removing sensitive fields) so you can reproduce issues more accurately without screen-sharing or installing tools.
• QA and automated test artifacts: Store session snapshots from end-to-end tests, compare them across releases, and confirm that refactors did not change key names, prefixes, or serialization formats unexpectedly.

Whether you are fixing a production incident or validating a new feature, having a readable view of sessionStorage helps you reduce guesswork and shorten the time from symptom to root cause. It also encourages better storage hygiene: when developers can see what is being stored and how big it is, it becomes easier to keep session storage lean and intentional.

Optimization Tips

Export a Minimal Snapshot

If you only need a subset of keys, export just what matters. Smaller snapshots are easier to share and less likely to include sensitive data. In many cases, a handful of keys like auth_token, return_url, and a single feature flag prefix are enough to debug the issue.

When you do need a full snapshot, consider exporting it right after the failing action, before redirects or tab refreshes can clear the state. That timing often captures the information you need most.

Keep Values Human-Readable

When your application writes complex objects, prefer concise JSON strings that are easy to parse and diff. Avoid storing minified blobs when you can store structured JSON, and keep a consistent schema so troubleshooting does not require guesswork.

If you must store encoded values, enable URL decoding and JSON parsing in the tool so you can review the content safely before copying it elsewhere. You can also cap the value preview length in the report format to keep output readable when values are very large.

Watch for Sensitive Fields

Session storage often holds tokens, email addresses, device identifiers, or internal IDs. Before sharing output publicly, redact or remove sensitive keys. A good practice is to rename keys to placeholders in bug reports and share the full snapshot only in secure channels.

When auditing storage, look for secrets that do not need to be client-side at all. Moving sensitive state to HTTP-only cookies or server-side sessions can reduce risk and simplify compliance.

FAQ