Tools that run in your browser. Plus a desktop app.
Your data never leaves your device.
No signup · No uploads · No server · Free forever
Sutnes PST Reader
Open and full-text search Outlook PST / OST mailbox files — no Outlook, no MAPI, no Microsoft 365. Stays fast on 10 GB+ archives, and your original PST is never modified. Free & open source for Windows 10/11.
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All tools →Why oToolRun
Three things make these tools different from the dozens of "free online" sites out there.
Private by design
Every tool runs in your browser. Your text, numbers, dates, and images stay on your device — there's no backend that processes your input. Verify it yourself in your browser's Network tab.
Instant results
No round-trip to a server, no spinners, no rate limits. Press Run and the answer appears. Pages are pre-rendered and served from a global CDN — typical first paint under 500ms anywhere in the world.
No signup, no fluff
No accounts, no email walls, no "upgrade to remove watermark." Every feature is free and stays free. The only thing supporting the site is unobtrusive display advertising.
oToolRun is a growing collection of small, single-purpose web tools — the kind of thing you'd otherwise reach for a spreadsheet, a stack of browser tabs, or a paid app to do. Every tool answers one question, finishes in milliseconds, and never sends your input to a server. The Sutnes PST Reader desktop app extends the same privacy-first idea to Outlook mailbox files.
Frequently asked questions
Are the tools really free?
Yes. There's no paid tier, no signup, no usage cap, and no watermark on output. Hosting is paid through display advertising via Google AdSense.
Is my data uploaded anywhere?
No tool input is sent to a server. Every utility runs entirely in your browser. Anonymized analytics are collected separately via Google Analytics and Microsoft Clarity.
What is Sutnes PST Reader?
A free Windows desktop app for opening and full-text searching Outlook PST and OST mailbox files — no Outlook required. It is a separate download; everything else on oToolRun runs in your browser.
Do I need to install anything?
No — every web tool works in any modern browser on desktop or mobile. Only the optional PST Reader desktop app is a download.