Converts MP4 files to MP3 format — universal video playback on any device to universal music playback and sharing across all devices and platforms. All conversion happens locally in your browser with no file size limits.
Runs on FFmpeg
Content reviewed October 2026 · About Toolzum
Extract the audio track from QuickTime MOV files and convert it to MP3 format. All processing runs locally in your browser with FFmpeg WASM — nothing is uploaded.
Extract the audio track from WebM video files and convert it to MP3 format. All processing runs locally in your browser with FFmpeg WASM — nothing is uploaded.
Create ZIP archives from your files right in your browser. Bundle loose files into one archive.zip with DEFLATE compression — local JSZip work, unlimited saves.
Extracts the audio track from uploaded video files (MP4, MOV, AVI, WebM) and encodes it as a high-quality MP3 file. Free to start with no signup.
Reduces MP4, MOV, and WebM video file sizes with a configurable CRF 20–40 slider (default 28, libx264 fast preset), plus a GIF mode with color-palette control. Videos never leave your device — compression runs locally in your browser with FFmpeg WASM.
MP4 (MPEG-4 Part 14) uses lossy compressed encoding and is best for universal video playback on any device — phones, smart TVs, web browsers, and social media. MP3 (MPEG-1 Audio Layer 3) uses lossy compressed encoding and excels at universal music playback and sharing across all devices and platforms. Converting between them lets you take advantage of each format's strengths — for example, using a compressed format for sharing and a lossless format for editing. All conversion happens locally in your browser with no file size limits.
Extracts the audio track from MP4 video files and saves it as a standalone MP3 file. All processing runs locally in your browser with FFmpeg WASM — nothing is uploaded.
universal music playback and sharing across all devices and platforms.
Complete, uncorrupted MP4 files convert cleanly. Partial downloads and truncated files fail or produce broken output — verify the source opens correctly first.
JSON to XML
Converts JSON files to XML format — APIs, configuration files, and data exchange between web services to enterprise systems, SOAP APIs, document formatting, and legacy integration pipelines.
Archive Converter
Create ZIP archives from your files right in your browser. Bundle loose files into one archive.zip with DEFLATE compression — local JSZip work, unlimited saves.
MKV to MP4
Convert MKV video files to MP4 format directly in your browser. 100% free, private — your files never leave your device.
EPUB to PDF
Converts EPUB files to PDF format — e-readers, mobile devices, and accessible digital books to document sharing, printing, and archival with consistent formatting. All conversion happens locally in your browser with no file size limits.
MP4 to MKV Converter
Converts MP4 files to MKV format — universal video playback on any device to advanced video archiving with multiple subtitle tracks, chapters, and audio streams in one file. All conversion happens locally in your browser with no file size limits.
MP4 to MOV Converter
Convert MP4 video files to MOV format directly in your browser. 100% free, private — your files never leave your device.