Preflight is a native macOS utility for checking a PDF against practical submission constraints before sending it — exact byte size, page count, searchable text, encryption, and page dimensions. When a PDF exceeds the selected limit, Preflight can create a separate, locally optimized copy at or below that limit. It never changes the selected source document, and it performs no network requests.
The complete documentation — everything Preflight can do, step-by-step Shortcuts and Finder Quick Action setup, comparison limits, and how optimization protects your files — is in the Preflight user guide.
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Email [email protected] — include your macOS version and, if you can, the check or step where things went wrong. Never send a confidential document.
No — never. Preflight reads the PDF you select to inspect, hash, and compare it, but it does not modify, overwrite, move, or delete it. Optimization always creates a separate new PDF in a location you choose. If Preflight cannot produce a safely preserved copy that meets your target size, it refuses and leaves you with exactly what you started with.
When you run Optimize to Fit in the app, Preflight asks you to choose a destination and writes the new PDF there. When you use the "Optimize PDF Under Size" Shortcuts action, the verified PDF is returned from Preflight's temporary storage — add Apple's Save File action immediately after it in your shortcut to keep the result, since Preflight does not save into the source folder.
Optimize to Fit is offered only when the selected PDF is actually over the active profile's exact byte ceiling. If the file already fits, there is nothing to optimize and the button stays out of the way.
Every output candidate must pass Preflight's preservation checks (page geometry and searchable text kept intact) and an independent exact-byte verification before it is exported. If no candidate can meet the target without degrading the document, Preflight fails honestly rather than hand you a broken file. Try a slightly larger target, a different optimization mode, or reduce the source document's content.
After launching Preflight once, open Apple's Shortcuts app and search for the Preflight actions: "Inspect PDF with Preflight" (returns the inspection findings as text) and "Optimize PDF Under Size" (takes a PDF and a target size in bytes, returns a verified PDF). To make a Finder Quick Action, create a shortcut whose input is Files from Finder, add a Preflight action, enable "Use as Quick Action" in the shortcut's details, and run it from Finder's right-click Quick Actions menu. Each action accepts one file per invocation. Step-by-step instructions are in the user guide at trolls.dev/preflight-guide.
In the app you can select or drop 2 to 100 PDFs for a sequential batch inspection under a frozen profile, review per-file results, optimize only the oversized eligible files into a chosen folder, and export a JSON or CSV batch receipt. Folders are not searched — Preflight only touches files you explicitly provide.
The optional "what is this PDF about" explanations and guideline-PDF import run entirely on your Mac using Apple's on-device Foundation Model. They require macOS 26 with Apple Intelligence enabled; every other feature works on macOS 14 or later. Explanations are composed only of verbatim passages verified against the PDF's own text, held in memory, and never written to disk.
None. Preflight has no network functionality and performs no network requests — documents, results, settings, and receipts never leave your Mac, and there are no accounts, analytics, ads, or trackers. The full details are in the privacy policy linked below.
Preflight collects no data and makes no network requests. The full policy is at trolls.dev/preflight-privacy.
Preflight is designed, built, and run by trolls.dev LLC, a small independent software studio. The story behind the app is in the Preflight case study.