Why private conversion matters
Most online converters upload your files to a server. That risks leaks, logs, and third-party access. ConvertFlow runs FFmpeg and canvas processing only in your browser — your media never leaves the device.
Read more →Video & Audio Converter
Convert formats entirely in your browser. Nothing leaves your device.
Speed:
Resolution:
Rotate:
🔒 No upload
Best under 500 MB
Files stay on device
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Drop one video or audio file, or click to browse
MP4 · MOV · MKV · WebM · MP3 · WAV · and more
How it works
1
Add files
Drop or select video/audio from your computer. The drop zone is replaced by a preview of your files. Nothing is uploaded.
2
Wait, then convert
Wait until the green “Engine ready” banner appears. Convert stays disabled until then. Pick MP4, MOV, MP3 or GIF and click Convert.
3
Download
When conversion finishes, the green Download button appears. Save the file instantly to your device.
Learn & stay private
Short guides on formats, privacy, and best practices.
MP4 vs MOV vs GIF: which to choose
MP4 is the universal web and phone format. MOV is common from Apple devices. GIF is for short, silent loops. Learn when each makes sense and what quality settings to use.
Read more →Instagram, YouTube & TikTok sizes explained
1080×1080 posts, 1080×1920 Stories/Reels/Shorts, 1280×720 thumbnails. Use the right preset so platforms don’t crop or stretch your image.
Read more →Faster conversions and smaller files
Keep resolution reasonable, use WebP or AVIF for photos, and prefer MP4 with H.264 for video. Browser conversion works best under a few hundred MB; very large files may need patience or a desktop tool.
Read more →How to remove audio from a video
Muting a video shouldn't mean re-encoding the whole file. Learn when a silent video actually helps — and how to strip audio instantly, without quality loss, entirely in your browser.
Read more →