Perflex Privacy Policy

Last updated: 2026-06-24

Perflex is a privacy-first, local-only browser extension. It does not require an account, does not track you, and does not upload your browsing or performance data to any server operated by us. We do not operate any server at all.

What Perflex does

Perflex measures and diagnoses the JavaScript performance of web pages you choose to profile. It captures performance signals from the page — long tasks, network request timings, layout shifts, memory usage, DOM activity, and similar metrics — and analyzes them entirely within your browser to produce a performance report and suggested fixes.

Data we collect

None is sent to us. All captured performance data is processed locally in your browser and held only for the duration of your session. We do not collect personally identifiable information, authentication credentials, financial information, health information, personal communications, location, or web-browsing history.

Local storage

The extension stores your settings locally on your device using the browser's extension storage. This includes: an optional AI provider API key — either an Anthropic Claude key or a Google Gemini key (if you choose to provide one) — a list of first-party domains you configure, and the viewer URL used for shareable links. This data never leaves your device except as described in “Optional AI features” below.

Optional AI features

The AI features are off unless you configure an API key, and they only work with your own key for the provider you select in Settings (Anthropic Claude or Google Gemini).

• AI Analysis (per finding): when you explicitly click it, Perflex sends an anonymized, non-identifying summary of that single finding (pattern name, script filename, function name, timing metrics) to your selected provider to generate a remediation.
• AI Coach (chat): when you send a message, Perflex sends an anonymized summary of the current session (health score, Core Web Vitals, top scripts by filename, findings) along with your message. URLs are reduced to site.com/path with query values removed.

In both cases, full URLs (including query strings or tokens), request/response bodies, and page content are never sent. Data is transmitted only to the provider you chose — Anthropic's API (api.anthropic.com, governed by Anthropic's privacy policy) or Google's Gemini API (generativelanguage.googleapis.com, governed by Google's privacy policy).

Sharing & exports

When you export a session or create a shareable link, the data is encoded on your device. Shareable permalinks place the encoded session in the URL fragment, which browsers do not transmit to any server. Exported files are saved locally. You control where any of this data goes.

Data sharing & sale

We do not sell, rent, or share your data with third parties. We have no analytics, no advertising, and no telemetry.

Permissions

Perflex requests broad host access (<all_urls>) and scripting permissions because, as a performance profiler, it must be able to instrument whichever page you choose to analyze. These permissions are used solely to capture and analyze performance data locally.

Contact

Questions or issues: github.com/svemulapati/perflex/issues.