How to Convert
Video Formats Online

A complete guide to video formats and how to convert between MP4, AVI, MOV, MKV, WEBM, and more — free, online, no software needed.

Video Format Comparison

Not all video formats are created equal. Here's what you need to know about each one:

FormatBest ForCompatibilityFile Size
MP4Everything — web, mobile, social mediaUniversalSmall
AVILegacy software, Windows applicationsWindows-centricLarge
MOVApple ecosystem, Final Cut ProApple + some WindowsMedium-Large
MKVMovies with multiple audio/subtitle tracksVLC, media playersVaries
WEBMWeb video, HTML5 playersBrowsersSmall
FLVLegacy Flash contentLimited (declining)Small
WMVLegacy Windows MediaWindows onlyMedium

Which Format Should You Use?

For Social Media
Use MP4. Every platform (YouTube, Instagram, TikTok, Twitter) accepts MP4 and it offers the best compression-to-quality ratio.
For Websites
Use MP4 or WEBM. MP4 has universal browser support. WEBM offers slightly smaller files for Chrome and Firefox.
For Editing
Use MOV (Apple) or AVI (Windows). These formats preserve more quality for post-production work.
For Archiving
Use MKV. It supports multiple audio tracks, subtitles, and metadata in a single container.

How to Convert Videos Online

  1. Go to the RnBulkTools Converter — no signup needed
  2. Upload your video — drag and drop or click to select. Files up to 500MB are supported.
  3. Choose your target format — select MP4, AVI, MOV, MKV, WEBM, or any other format from the dropdown.
  4. Click Go — conversion happens on our server using FFmpeg. Download when complete.

You can queue up to 5 videos and convert them all at once.

Common Conversions

MOV to MP4

The most common conversion for iPhone users. MOV files from your iPhone camera can be large and incompatible with some platforms. Converting to MP4 reduces file size and ensures universal compatibility.

AVI to MP4

AVI is a legacy format that produces large files. Converting to MP4 typically reduces file size by 50-80% with minimal quality loss.

MKV to MP4

MKV is great for archiving but doesn't play natively on many devices. Converting to MP4 makes your videos playable on phones, tablets, smart TVs, and any media player.

Video to Audio

RnBulkTools also extracts audio from video. Convert MP4 to MP3, MOV to WAV, MKV to FLAC — any video format to any audio format.

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