← Local Data Tools

File Viewer: Preview Any File Locally, No Upload

Drop in a spreadsheet, PDF, document, image, or media file and see it instantly without an app or a server round-trip. The File Viewer reads everything in your browser tab, so a confidential client XLSX or a sensitive PDF never leaves your machine. Switch between sheets in a workbook, scroll large tables, and export the view back out to CSV or XLSX when you need it. Handy when you get a file in an odd format and just want to look inside before deciding what to do with it.

Frequently asked questions

Does the File Viewer upload my files anywhere?

No. Files are read and rendered entirely inside your browser tab using WebAssembly. Nothing is sent to a server, so it works offline and your data stays on your device.

What file types can it open?

Spreadsheets (CSV, XLSX, XLS, ODS), documents (PDF, DOCX, TXT, Markdown), data and code (JSON, JS, TS, HTML, CSS, XML, logs), plus images, audio, and video.

Can I open large spreadsheets without it freezing?

Yes. Big tables render in chunks and load more rows as you scroll, so wide multi-sheet workbooks stay responsive instead of locking up the tab.

More free tools

Every tool runs entirely in your browser. Files are never uploaded — 100% private and free.