Every office job eventually runs into the same wall: the file you have is not the file you need. A recruiter wants a PDF, your accountant wants a spreadsheet, your developer wants JSON, and the government portal only accepts CSV. You could install a desktop suite for each job, but in 2026 the fastest answer is almost always a free browser-based converter — as long as you pick one that doesn't hold your document hostage behind a sign-up form or stamp a watermark on page one.

This guide rounds up the best free ways to convert the six most common document formats — Word, PDF, Excel, CSV, and JSON — and explains what to watch for with each conversion. Every tool linked here is part of the free Toolyfied suite: no account, no watermark, no daily limits, and files up to 50 MB processed right in your browser.