We built DataLens Pro on a simple principle: your data belongs to you — and it never leaves your device.
DataLens Pro is a Chrome Extension that lets you analyze, visualize, and export Excel and CSV files entirely within your browser tab. All parsing, statistics, charts, pivot tables, and export functions run as client-side JavaScript with no server involvement.
| Data | Stored In | Purpose | Transmitted? |
|---|---|---|---|
| uploadCount — integer | chrome.storage.local |
Track monthly file uploads against the 20/month free limit | Never |
| resetMonth — "YYYY-MM" string | chrome.storage.local |
Auto-reset the upload counter at the start of each new calendar month | Never |
| isPro — boolean | chrome.storage.local |
Remember whether a Pro license has been activated | Never |
| licenseKey — alphanumeric token | chrome.storage.local |
Validate Pro license locally using a hash function on-device | Never |
| theme — "light" or "dark" | chrome.storage.local |
Remember your preferred visual theme between sessions | Never |
| totalRowsAnalyzed — integer | chrome.storage.local |
Display your monthly usage statistics in the app | Never |
| Data | How It's Used |
|---|---|
| uploadCount + resetMonth | Checked locally each time you open a file to determine remaining free uses. Reset to 0 automatically on the first day of each month. |
| isPro + licenseKey | Checked locally to unlock Pro features. The license key is validated by a hash algorithm running entirely on your device — it is never sent to any server for verification. |
| theme | Applied immediately on launch to restore your preferred dark or light appearance. |
| totalRowsAnalyzed | Displayed in the stats strip on the upload screen to show your monthly usage. Never used for any other purpose. |
When you open an Excel or CSV file in DataLens Pro:
FileReader API — it never touches a serverUsed to save the five small values listed in Section 2.1 to your local device. No spreadsheet data is ever stored here.
Used exclusively to open DataLens Pro as a full browser tab (rather than a small popup) when you click the extension icon. We do not read, modify, or access any other tab you have open.
activeTab, scripting,
webRequest, or any host permission (<all_urls>).
It does not read, inject code into, or interact with any webpage you visit.
| Service | Purpose | Data Shared |
|---|---|---|
| Google Fonts fonts.googleapis.com |
Load the "Plus Jakarta Sans" typeface for the UI | Standard HTTP request — no user data, no file contents |
| bKash | Payment processing (Bangladesh) | Payment handled entirely outside the extension via your bKash app. We receive only a transaction screenshot to issue your license key. |
| Payoneer | Payment processing (International) | Payment handled entirely outside the extension. We receive only transaction confirmation. |
We do not use Google Analytics, Firebase, Mixpanel, Sentry, or any other analytics, tracking, or crash-reporting service.
To delete all stored data manually: go to Chrome Settings → Extensions → DataLens Pro → Details → Clear Data.
DataLens Pro does not knowingly collect any personal information from children under the age of 13. Since the extension collects no personal information from any user, it is safe for use by all ages. If you believe a child has provided personal information through our extension, please contact us and we will address it promptly.
Because DataLens Pro does not transmit any user data to external servers, the attack surface for data breaches is minimal. The license key validation uses a local hash function — no server-side validation endpoint exists that could be compromised. All extension code is delivered through the Chrome Web Store, which applies its own security scanning.
If we update this Privacy Policy, we will revise the "Effective Date" at the top of this page and release a new version of the extension through the Chrome Web Store. We will never change this policy to allow collection or transmission of your file data — that is a core architectural commitment, not just a policy choice.
For privacy questions, data requests, or general support, reach us through any of the channels below.