Convert media between MP4, WebM, MP3, WAV, OGG, GIF and more — in your browser.
Notes
Was this tool helpful?
96% · 263 people found this tool helpful
Convert video and audio files between MP4, WebM, GIF, MP3, WAV, OGG and M4A entirely in your browser using FFmpeg.wasm. Nothing is uploaded — the file stays on your device, the conversion runs in WebAssembly, and the result downloads from your own machine. Useful for shrinking a video for messaging, extracting audio from a clip, or creating a quick GIF preview without installing desktop software.
Drag and drop Video & Audio files into the drop zone, or click to browse — batch conversion is supported.
See a live preview of the the target format output before you commit, so you can catch any surprises early.
Save the converted the target format to your device — everything happens in your browser, so nothing is uploaded to a server.
Format conversion is one of those chores you never plan for — a colleague sends a file in the wrong extension, a client app rejects your upload, a legacy system refuses anything but its native format. Video & Audio Converter exists so that you never have to install a desktop app or trust a random uploader website just to change a file's container. Everything runs inside your browser tab using modern WebAssembly builds, which means your files are never transmitted, queued, or logged. Toolzer's design philosophy is simple: privacy-first (no tracking, no accounts), performance-first (the page is interactive in under a second on a 3G connection), and honesty-first (no fake ratings, no dark patterns, no upsells). Video & Audio Converter follows the same rules as every other utility on the site. You can bookmark this page, share the URL with a colleague, or pin it to your browser's toolbar — the experience will be identical every visit, and it will keep working even if you're on airplane Wi-Fi. Real people use this tool for real work — freelancers cleaning up client deliverables, sysadmins triaging tickets, students finishing assignments — and it is tuned for those workflows, not for demo videos.
How Toolzer compares to typical online alternatives.
| Feature | Toolzer | Typical competitors |
|---|---|---|
| Price | 100% free | Free with limits or paid |
| Signup required | No | Usually yes |
| Data privacy | Processed in your browser | Uploaded to their server |
| Watermark | Never | Often on free tier |
| File size limit | Generous / none | Usually 5–10 MB |
| Ads | Minimal | Heavy, intrusive |
| Mobile friendly | Yes | Often not |
The FFmpeg WebAssembly bundle (~25 MB) loads on first use and is cached for subsequent runs in the same session.
Browser memory is the limit. Most modern devices handle 200–500 MB videos; very long 4K files may run out of RAM.
We use sensible defaults: H.264 / AAC for MP4, VP9 / Opus for WebM, 192 kbps for MP3. They balance quality and file size for general use.
No. The file never leaves your browser tab — everything happens client-side via WebAssembly.
No. Every utility on Toolzer is free, anonymous, and works in any modern browser without registration.
Yes. Whenever the tool can produce an answer entirely in the browser, the data never leaves your device.
Yes. The interface is fully responsive and works on iOS Safari, Android Chrome, and every modern mobile browser.
Yes. Every Toolzer page has a clean permanent URL you can bookmark or share.
Large images are the single biggest cause of slow web pages.
Resizing an image without distorting it means keeping the same width-to-height ratio.
A complete color workspace in your browser.
The Video to GIF is a fast, single-purpose tool that focuses on doing one job well.
The Compress Video is a fast, single-purpose tool that focuses on doing one job well.