Free File Converter

Convert between Markdown and HTML, or CSV and JSON, instantly in your browser. Copy or download with the correct extension. 100% private and free.

Also try

Related guides

Convert Files Between Markdown, HTML, CSV & JSON Instantly

Our free file converter handles four essential transformations entirely in your browser — no uploads, no server processing, and no account required. Convert Markdown to HTML for publishing, HTML to Markdown for content archival, CSV to JSON for API integration, or JSON to CSV for spreadsheet analysis. Each conversion preserves formatting and structure, with output automatically assigned the correct file extension for immediate download.

Why Use Our File Converter?

  • Four conversions in one tool: Markdown ↔ HTML and CSV ↔ JSON — cover your content and data workflows without switching apps.
  • 100% private & offline: All parsing and serialization happens locally; your files and data never leave your device.
  • Instant results with correct extensions: Download .html, .md, .json, or .csv files ready to use — no manual renaming.
  • Free, unlimited, no sign-up: Convert as many files as you need, any size your browser can handle.

How to Convert Files

  1. Select the conversion direction: Markdown to HTML, HTML to Markdown, CSV to JSON, or JSON to CSV.
  2. Paste your source content or upload a file — the input panel accepts both text and file drops.
  3. Click Convert — the formatted output appears instantly in the preview panel.
  4. Copy the result or click Download to save with the proper file extension.

Need to turn converted Markdown into a polished document? Use our JPG to PDF tool for image-based PDFs, or the PDF to Images tool to extract pages as PNG or JPG files.

Frequently Asked Questions

What conversions are supported?

Markdown to HTML, HTML to Markdown, CSV to JSON, and JSON to CSV — four conversions in one tool.

Is my data private?

Yes. All conversions happen locally in your browser. Nothing is uploaded to a server.

Can I download the converted output?

Yes. Download your result and it automatically gets the correct file extension (.html, .md, .json, or .csv).

Is the converter free?

Yes. All four conversions are completely free with no limits or sign-up.

When should I use each conversion?

Use Markdown to HTML when publishing docs, HTML to Markdown when saving web content, CSV to JSON for API integration, and JSON to CSV for spreadsheet analysis.