About & Privacy

How Rosetta Check works and how we protect your privacy.

What is Rosetta Check?

Rosetta Check is a macOS app and companion website. The app scans your Mac to identify which installed applications are Intel-only, Universal, or native Apple Silicon. This website aggregates data contributed by Mac users who opt in, helping the community see which Intel apps are most common and surface AI-generated migration guidance for each one.

As Apple removes Rosetta 2 in macOS 28 (late 2027) — knowing which apps need attention helps you plan ahead.

Who builds Rosetta Check

Rosetta Check is a single-developer project, built and maintained by Neil Johnson. The macOS app, the catalogue website, the blog posts and the data analysis behind them are all the work of one person in their own time. There is no team, no investors and no third-party SDKs.

The project exists because the Apple silicon transition is mostly described in headlines and rarely in numbers. Rosetta Check aggregates anonymous, opt-in scan data from thousands of Macs so the picture is grounded in what people are actually running, not what vendors say they support.

Find me on LinkedIn or X (@jonnokid).

Privacy: The macOS App

The Rosetta Check macOS app is private by default. All scanning happens locally on your device. Community Sharing is off by default; scan results are not transmitted unless you or your administrator enable it.

What the app accesses on your Mac

  • Application metadata (name, version, architecture) via Spotlight
  • Mach-O headers and static code-signing metadata for apps, components, and command-line Tools
  • File modification dates to show when apps were last updated
  • App bundle sizes to show disk usage
  • Folders you explicitly grant through the macOS read-only folder picker
  • UserDefaults to store your preferences (like scan on launch)

What the app does not do

  • Does not collect personal information of any kind
  • Does not execute discovered command-line Tools
  • Does not include analytics, telemetry, or tracking frameworks
  • Does not access contacts, photos, location, or other sensitive data
  • Does not sell data or share it for advertising

The app runs inside the macOS App Sandbox with minimal entitlements. It is built entirely with Apple's native frameworks (SwiftUI, Foundation, AppKit) and contains zero third-party services or SDKs.

Privacy: Contributing Data

Contributing scan results is entirely optional and requires a deliberate action. When you choose to contribute, the app sends only a minimal summary of your Intel-only apps, components, and package-level Tool blockers — no personal information or file contents are included.

What is sent when you contribute

Data Example Purpose
App name Microsoft Word Display in directory
Bundle ID com.microsoft.Word Unique identification
Tool product key homebrew:formula:ffmpeg Group commands by package or signed product
Bare Intel command names ffmpeg, ffprobe Show which commands still need Rosetta
Version 16.82 Track updates
Category Productivity Filtering and grouping
Disk size 2.1 GB Show storage impact
Impact score 73 Prioritise by relevance
Chip family Apple M3 Pro Hardware context
Device hash a3f8...c912 Prevent duplicate counting

What is never sent

  • Your name, email, Apple ID, or any login credentials
  • Your IP address (the server does not store it)
  • Any files, documents, or personal data
  • Tool paths, usernames, symlink targets, folder grants, or file contents
  • Apple system Tools or unmanaged unsigned/ad-hoc Tools
  • Native software inventories; native matches are reported only for server-tracked keys
  • Anything that could identify you as a person

The device hash is random, not derived from your hardware. When you first run Rosetta Check, the app generates a random identifier and stores it locally in the macOS keychain. We use it only to avoid counting the same device twice in our totals. It is not based on your serial number, IOPlatformUUID, or any other Apple identifier, and it cannot be linked to you or your Mac.

Privacy: This Website

  • No cookies (except Cloudflare's security cookie, which we do not control)
  • No user accounts or login required
  • The server does not store IP addresses long-term

Website Analytics

We use Plausible Analytics — a lightweight, open-source, privacy-friendly analytics tool.

  • No cookies set by Plausible
  • No personal data collected or stored
  • No cross-site or cross-device tracking
  • All data is aggregated — individual visitors are never identified
  • Fully compliant with GDPR, CCPA, and PECR without a cookie banner

Plausible does not use cookies, fingerprinting, or persistent identifiers. Page views are counted using a hash of the visitor's IP and User-Agent, discarded every 24 hours. Plausible's data policy.

AI Recommendations

For each Intel-only app we generate a recommendation that explains what the app does and how to handle it before Apple removes Rosetta 2 in macOS 28 (late 2027) — whether that means downloading a native build, switching to a maintained alternative, or accepting that the app has been abandoned. AI-generated entries are clearly labelled. The directory also accepts community-submitted suggestions, which our team verifies with a checkmark after manual review.

Community Spotted

When Community Sharing is enabled, Rosetta Check downloads the app/component bundle IDs and Tool product keys already tracked as Intel blockers. If the Mac has a native or Universal version matching one of those keys, the app explicitly reports a "sighting". It never uploads a general native-software inventory.

What is sent for a sighting report

  • The app/component bundle ID or Tool product key
  • The native version number detected
  • The reported CPU architecture (e.g. Apple Silicon)
  • Your device hash (the same random identifier used for contributions)

How your privacy is protected

  • Sighting reports contain no personal information — only the tracked key and compatibility metadata
  • The device hash is randomly generated and cannot be linked to you or your Mac
  • Reports are rate limited per anonymous device to prevent spam
  • Only devices that have previously contributed can report sightings
  • The website only displays an aggregate count (e.g. "Spotted · 6") — individual reports are never shown

Sightings are deliberately narrow. They contain only a server-tracked key, native version, CPU architecture, and the same random device hash used for contributions. No additional identifiers, paths, or file contents are introduced. Your IP address is not stored.

Get the macOS App

Download Rosetta Check for macOS to scan your system and optionally contribute to the community dataset.

This privacy policy is effective as of February 2026. Last updated August 2026.

Questions? Contact [email protected]