Drop your file here

or click to browse

TXT, MD, JSON, XML, HTML, CSS, JS, LOG, YAML, CSV, TSV, XLSX, XLS

Online File Editor

A fast, private, browser-based file viewer and editor. Open files from your device, view them in a clean formatted layout, make edits, and download — all without uploading anything to a server.

Your files stay on your device. This tool processes everything locally using browser APIs. No file content is ever uploaded, transmitted, or stored on any server.

Features

Multi-Format Support

View and edit TXT, Markdown, JSON, XML, HTML, CSS, JS, YAML, CSV, TSV, XLSX, and XLS files.

Inline Editing

Switch to edit mode to modify text files directly, or click individual cells in table view for CSV and XLSX data.

Markdown Preview

Markdown files render with full GitHub-Flavored Markdown support — headings, tables, code blocks, task lists, and more.

Download Modified Files

Save your changes and download the file in its original format — including reconstructed XLSX spreadsheets.

Supported Formats

.txt .md .json .xml .html .css .js .log .yaml .yml .csv .tsv .xlsx .xls

How to Use

Upload Your File

Drag and drop a file onto the upload zone, or click to browse your device. Supports 14 file formats.

View Formatted Content

Files display in the best view for their type: code with monospace formatting, Markdown with rendered preview, or data in interactive tables.

Edit if Needed

Click "Edit Mode" to switch to a text editor for code/text files, or click cells directly in table view for CSV and spreadsheet data.

Download Your File

Click "Download" to save the file with your changes. XLSX files are reconstructed as valid spreadsheets using SheetJS.

Frequently Asked Questions

Is my file uploaded to any server?
No. Your file is read entirely in your browser using the File API. No data is transmitted over the network. The tool works even with your internet connection turned off after the page loads.
Can I edit Excel spreadsheets?
Yes. XLSX and XLS files are parsed using the SheetJS library and displayed as interactive tables. You can click any cell to edit it in edit mode, then download the modified file as a valid spreadsheet.
What is the maximum file size?
There is no hard limit — the maximum depends on your browser's available memory. Most browsers handle files up to several hundred megabytes, but very large files may cause the tab to slow down.
Does the Markdown preview support GitHub Flavored Markdown?
Yes. The preview uses the marked.js library which supports full GFM — including tables, task lists, strikethrough, fenced code blocks, and auto-linked URLs. HTML output is sanitized with DOMPurify for security.