CSV Preview

CSV Preview is a CSV viewer that runs entirely in the browser. You open, paste or drag a file in, and it appears as a table you can sort, filter and scroll with the header row pinned in place. The file never leaves your computer. There are no accounts, no uploads and no server parsing anything. It's for the moment when someone sends you an export and you want to look at it properly without launching a spreadsheet application or handing the data to a random upload site.

The privacy model is the whole point and the site states it without hedging. Your data never leaves your browser. That matters more than it sounds for the files people actually open, customer lists, payroll exports, support tickets, anything with a name and an email address in it. Because the parsing happens on your machine, you can inspect a sensitive file with the same confidence you'd have opening it locally, and the browser's local storage keeps your place so you can close the tab and come back to resume where you were.

The viewer covers the basics well. A first row as header option turns the top line into column names, rows are numbered, and headers stay pinned while you scroll a long file. Single-click column sorting flips between ascending and descending. Filtering works three ways, by picking values from a column, by searching for text, or by numeric comparison, which is enough to answer most quick questions, like how many rows sit above a threshold or which entries mention a given city. There's a copy function for pulling what you found back out into whatever you're working in. A typical use takes seconds. Drag the export onto the page, tick first row as header, sort by the column you care about, filter down to the rows that match, and copy the result out. The pinned header means a thousand-row file is as readable at the bottom as at the top, and if you close the tab, local storage brings the file back when you return, so a half-finished check doesn't have to start again from the file picker.

Compared with a spreadsheet application, it's lighter, faster to open and asks nothing of your machine beyond a browser tab. Compared with the many online CSV viewers that upload your file to a server first, the difference is the one that matters for anything confidential, the file stays where it is. That's also why there's no login and no history on a server anywhere. There's nothing to log into because nothing about your file ever leaves the page.

Around the viewer sits a small set of tools, all of which also run in the browser. CSV to Excel takes one or several CSV files and produces an Excel workbook, either merged into a single file or delivered separately. Excel to CSV does the reverse, splitting a workbook into one CSV per worksheet and zipping them for download. The site also hosts sample datasets across geography, transport, economics, history, food, animals, science, language and architecture, which are handy for testing an import or teaching a class. Converting an Excel workbook into per-sheet CSVs is a common chore before a database import, and having it in the same tab as the viewer saves a round trip through a spreadsheet application.

It fits developers checking a database export before importing it, analysts glancing at a file before it goes into a pipeline, support staff opening a customer's attachment, and teachers who need a clean dataset in a hurry. Anyone whose employer would frown at uploading a file to an unknown website is the core audience, and so is anyone who has waited for a heavy spreadsheet application to launch just to look at twenty rows. Because it's a web page, it also works on a machine where you can't install anything, a locked-down work laptop or a borrowed computer. It was built independently by Anshul Sahni, inspired by jsonhero.io, the JSON viewer that takes the same one-thing-well approach. The design choice is deliberate. It doesn't try to be a spreadsheet, a database or a dashboard. It opens a file, lets you look at it properly, and stays out of the way, which is exactly why it loads quickly and why there's nothing to sign up for.

The limits are honest ones. The site describes viewing, sorting and filtering, not cell editing, so changes still happen elsewhere. There's no published file size limit, and very large files depend on what your browser can hold in memory. It's a one-person side project with a narrow CSV and Excel focus. Access is free, the tools page says $0 forever, and there's a contact address for the developer, anshul_sahni@live.com, on the about page. If you need a viewer for a file you'd never upload, this is the kind of tool you bookmark and forget about until the next export lands in your inbox.