PST & OST Viewer Upstairs

Upstairs opens Microsoft Outlook .pst and .ost mail archives, plus .mbox mailboxes from Google Takeout or Apple Mail, and lets you read what's inside them, on your iPad and your Mac, entirely offline. You probably have one of these files. An export from a job you left, a Google Takeout download of your Gmail, a backup from a computer you no longer own, an archive someone handed you on a drive. It is full of things you might need, and nothing on your Mac or iPad will open it. Upstairs will. BROWSE IT LIKE MAIL Your folder tree, exactly as it was. Message lists with senders, dates and attachment markers. A reading pane that renders the message the way it was written, formatting intact. FIND ANYTHING Full-text search across subjects, bodies, senders and recipients, with the matching words highlighted in context. Search covers the whole archive, not just the folder you're looking at, and accents are ignored so "cafe" finds "café". GET THINGS BACK OUT Export any message as a .eml file that opens in Mail, Thunderbird, or anything else. Save attachments to disk. Export a whole folder at once. BUILT FOR BIG ARCHIVES A ten gigabyte file is not a problem. Upstairs memory-maps the archive and indexes it in the background, so you can browse while it works. NOTHING LEAVES YOUR DEVICE This is the part that matters, and we mean it literally: • Upstairs ships without network permission. Not "we promise not to upload". The app has no ability to open a network connection. You can verify that yourself by inspecting the app bundle. • No account, no sign-in, no server. There is no database of you anywhere, because there is no server to hold one. • No analytics, no crash reporting, no advertising identifiers, nothing. • Remote images in messages stay blocked until you explicitly ask for them, so opening a five-year-old newsletter doesn't tell the sender you're still reading. • Your archive is opened read-only. Upstairs cannot modify it even by accident. WHAT'S SUPPORTED Unicode .pst and .ost archives from Outlook 2003 and later, including compressed and encoded archives. And .mbox mailboxes (the format Google Takeout uses for Gmail exports and Apple Mail uses for its own), with Gmail's labels appearing as folders. The older 32-bit ANSI PST format from Outlook 97-2002 is not supported yet. Upstairs will tell you clearly if you open one rather than failing silently. FREE AND PREMIUM Browsing and search are unlimited and free, forever. The free tier opens five messages, enough to check the archive really is what you think it is. Premium removes that limit and unlocks export. Premium is a one-time purchase. There is no subscription. You buy it once, it covers your Mac, iPad and iPhone, and it stays yours on devices you buy later. Most people open Upstairs because they have one archive they need to get into, and charging a recurring fee for a job you do once would be wrong.