SumoMorph is a free collection of 111 online tools for converting documents — PDFs, Word files, spreadsheets, structured data and text. It is built around a single principle that shapes every tool on the site: your files are yours, and they should never have to leave your device to be converted.
Most online converters upload your file to a server, process it there, and send it back. That means private contracts, invoices and records travel across the internet and sit on someone else's computer, even if only briefly. SumoMorph takes a different approach. Every tool here runs entirely inside your web browser using WebAssembly, the File API and the same open-source libraries that power professional software.
When you convert a file here, it is read, processed and saved on your own device. Nothing is uploaded, nothing is stored on a server, and nothing is logged. Conversions are faster because there is no upload or download to wait for, and your data stays private — we could not see your files even if we wanted to.
The toolkit covers the everyday document problems people actually hit: turning a Word document into a PDF, merging or splitting PDFs, pulling text out of a PDF, reshaping CSV into JSON for an API, reading a spreadsheet without opening Excel, or running OCR on a scan. There are developer utilities too — a JSON formatter, encoders, and archive tools — plus in-depth guides on choosing between formats.
A browser is a genuinely good place to convert a file, but it is not an unlimited one. Very large files run into the memory ceiling your browser imposes. Converting Word or PowerPoint to PDF with the original pagination intact needs a real layout engine, which no JavaScript library provides. And a browser cannot walk a folder and convert two thousand files unattended.
Those are real walls, not artificial ones, and they are exactly what SumoMorph Desktop exists to remove. The web tools stay free and complete; the desktop app is for the work the browser genuinely cannot do.
SumoMorph carries no advertising and sets no advertising cookies. The site is funded by SumoMorph Desktop, a one-time purchase for people who need batch conversion, true-fidelity office documents or unlimited file sizes. That means there is no incentive to keep you on a page, and no third party watching what you convert.
Have a question, found a bug, or want a format we do not support yet? Every message gets read — see the contact page.