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CHARTDIFF
AERONAUTICAL PDF COMPARATOR · CHROME EXTENSION
Privacy Policy
Last updated: April 2026 · Effective immediately upon installation
ChartDiff is a single-purpose Chrome extension. Its sole function is to compare two PDF documents open in the user's Chrome browser tabs and display the differences between them. The extension is designed specifically for aeronautical chart and publication workflows.
CORE PRINCIPLE
All document processing occurs exclusively on the user's local machine, inside the Chrome browser. No document content, metadata, or user information is ever transmitted to any external server.
ChartDiff does not collect any of the following:
✕Personal identifiable information
✕Health information
✕Financial information
✕Authentication credentials
✕Personal communications
✕Location or IP address
✕Browsing or web history
✕User activity or keystrokes
✕Website or document content
✕Cookies or tracking data
When the user selects two PDF tabs for comparison, ChartDiff reads the binary content of those PDF files directly within the browser. This content is loaded into browser memory solely for the purpose of rendering and comparing the two documents.
Document content is never written to disk by the extension, never sent to any remote server, and is discarded from memory when the side panel is closed or a new comparison is initiated.
ChartDiff reads the URL and title of open browser tabs solely to identify which tabs contain PDF documents. This information is used only within the active session to populate the tab selection interface and is never stored or transmitted.
ChartDiff requests the minimum permissions necessary to perform its function:
PERMISSION
REASON
tabs
To read the URL and title of open browser tabs in order to detect which tabs contain PDF documents for the user to select.
sidePanel
To display the ChartDiff comparison interface in Chrome's side panel alongside the user's open tabs.
scripting
To interact with the browser tab environment during the PDF content loading process.
storage
To retain the user's preferred diff mode setting (Text, Visual, or Both) across sessions. No document content or personal data is stored.
file://*/*
To access PDF files stored on the user's local filesystem when the user explicitly selects a local file tab for comparison. This permission is exercised only on demand and only for files the user selects.
<all_urls>
To fetch PDF content from any URL the user selects for comparison, including PDFs served over HTTPS from remote servers.
ChartDiff loads the PDF.js library (version 3.11.174) from the Cloudflare CDN (cdnjs.cloudflare.com) to parse and render PDF documents locally within the browser.
PDF.js is an open-source library maintained by Mozilla and is the same PDF rendering engine used by Chrome's built-in PDF viewer. No user data, document content, or personally identifiable information is transmitted to Cloudflare beyond a standard HTTPS asset request to download the library file.
NOTE FOR RESTRICTED ENVIRONMENTS
Users operating in air-gapped networks, classified environments, or systems with restricted outbound internet access should be aware of this external CDN dependency. A fully offline version of ChartDiff with PDF.js bundled locally is available on request.
ChartDiff does not sell, transfer, or share any user data with any third party under any circumstances.
User data is not used for purposes unrelated to the extension's single purpose of PDF document comparison.
User data is not used to determine creditworthiness or for any lending purpose.
ChartDiff is a professional productivity tool intended for use by aviation professionals, aeronautical information service staff, flight operations personnel, and document management teams. It is not directed at children and does not knowingly interact with users under the age of 13.
Any material changes to this privacy policy will be reflected in an updated "Last updated" date at the top of this page and communicated through the Chrome Web Store listing update notes.
For privacy-related questions or concerns regarding ChartDiff, contact the developer through the Chrome Web Store developer profile page.
CHARTDIFF · AERONAUTICAL PDF COMPARATOR
Chrome Web Store Extension · Manifest V3
This policy applies to the ChartDiff Chrome extension only.