Fitcheck Privacy Policy

Last updated: May 11, 2026

Fitcheck is a Chrome extension that gives you personalized sizing recommendations on fashion product pages. This policy explains what data the extension accesses and how it is handled.

This privacy policy applies to the Fitcheck Chrome extension and any optional companion local API process that the user chooses to run on their own machine.

Data we collect

Fitcheck does not operate its own remote data-collection server. By default, user data stays on your device unless you explicitly enable optional third-party provider integrations described below.

• Your profile (usual sizes, fit preferences, optional body measurements) — stored only in chrome.storage.local on your machine.
• Brand notes and fit history — stored only in chrome.storage.local.
• Product page content — the extension reads DOM content from fashion product pages only after you open Fitcheck from the Chrome toolbar on the current tab, in order to extract size charts, size options, and fit signals. This content is processed locally and is never transmitted to any Fitcheck server.
• Optional local cache files — if you run the companion local API, it may cache search evidence and token/rate-limit metadata in local files on your machine.

Local API

If you choose to run the optional local API (npm run api), it runs on your machine at 127.0.0.1:8787 and is intended to accept localhost connections only. When enabled, the extension sends product data and your profile to this local process. The local API may call third-party services you configure:

• Gemini (Google AI) — if you set a Gemini API key and enable model-assisted mode. Product data (brand, title, size chart) is sent to Google's API. Your personal measurements and profile are included in the prompt.
• Firecrawl / Brave Search — if you provide a search API key and enable web evidence mode. Queries like "Brand sizing reddit" are sent to the respective search provider. No personal data is included in search queries.

All third-party API keys are stored in a .env file on your machine. They are never stored in the extension or transmitted by the extension itself.

By default, the local API is intended for personal localhost use and does not require a user-issued API token unless the operator explicitly enables token enforcement.

How we use data

• To extract visible sizing information from the current product page.
• To generate and improve the size recommendation shown to you.
• To save your preferences, fit history, and brand-memory notes locally so future recommendations can be more accurate.
• To optionally retrieve web evidence or model-assisted analysis only when you configure those features.

Permissions used

• activeTab — read the current tab's URL and send messages to the content script.
• scripting — inject Fitcheck into the current tab only after you open the extension from the toolbar.
• storage — save your profile, history, and brand notes locally.

Data sharing

Fitcheck does not share, sell, or transmit your data to any third party, except as described above when you explicitly configure a third-party API key.

Advertising and sale of data

Fitcheck does not sell personal information. Fitcheck does not use user data for advertising, marketing profiles, or unrelated analytics.

Store disclosure summary

Fitcheck accesses page content only on the current tab after you invoke it, and uses that data only to provide the visible sizing recommendation feature. Fitcheck does not sell data or use it for advertising.

Data retention

All locally stored data (profile, history, brand notes) remains on your device until you clear it via the Fitcheck options page or uninstall the extension.

Your choices

• You can choose not to use the extension on any page by not invoking it.
• You can disable optional web evidence or model-assisted analysis.
• You can clear locally stored profile and history data from the Fitcheck options page.
• You can uninstall the extension at any time to remove extension-managed local data.

Contact

If you have privacy questions, contact the Fitcheck publisher at varun.gangadharan.63@gmail.com.

Fitcheck is open-source software. Your data is yours.