Free File Converter Tools Online
Convert CSV to JSON, JSON to CSV, MP4 to MP3, MP3 to WAV, TXT to PDF and Markdown to PDF โ free, instant, no signup.
All Converters โ 31 Free Tools
What You Can Do with Converters
- โConvert CSV spreadsheets to JSON with automatic column detection
- โExport JSON arrays to CSV for Excel and Google Sheets
- โConvert plain text files to formatted PDF documents
- โRender Markdown to beautifully styled PDF with tables and code blocks
- โExtract MP3 audio from MP4, MOV, AVI, and MKV video files
- โConvert MP3 audio to uncompressed WAV format
- โFiles automatically deleted after 2 hours
- โNo file size limits for standard conversions
Who Uses Converters?
Developers
Convert CSV exports to JSON for APIs and data pipelines
Content Creators
Extract audio from videos for podcasts and music
Writers
Convert Markdown docs to shareable, printable PDFs
Data Analysts
Switch between JSON and CSV for different tools
About Converters
File conversion is one of the most common everyday tasks for professionals, developers, and content creators alike. ToolNest's converter tools handle the most-needed format conversions in seconds, entirely in your browser with no software to install.
Whether you're a developer who needs to convert a CSV export to JSON for an API, a content creator extracting audio from a video file, or a writer turning a Markdown document into a polished PDF โ ToolNest has you covered with fast, accurate, free conversions.
Frequently Asked Questions about Converters
Can I convert multiple files at once?
Each converter processes one file at a time. For batch conversions, submit each file separately โ jobs run in parallel on our servers.
How does CSV to JSON work?
ToolNest reads the first row as column headers and converts each subsequent row into a JSON object, producing an array of objects as output.
What video formats does MP4 to MP3 support?
You can upload MP4, MOV, AVI, and MKV video files. The audio track is extracted and saved as a 192kbps MP3.
Is my data safe during conversion?
Yes. Files are uploaded over HTTPS, processed on secure servers, and automatically deleted within 2 hours. We never read, share, or retain your content.
Does Markdown to PDF support code blocks and tables?
Yes. Our Markdown renderer supports fenced code blocks, tables, blockquotes, and standard formatting โ all styled in the output PDF.